Postal censorship is the inspection or examination of mail, most by governments. It can include opening and total or selective obliteration of letters and their contents, as well as covers, postcards and other postal packets. Postal censorship takes place but not during wartime and periods of unrest, at other times, such as periods of civil disorder or of a state of emergency. Both covert and overt postal censorship have occurred. Postal censorship is an ancient practice. Both civilian mail and military mail may be subject to censorship, different organisations perform censorship of these types of mail. In 20th-century wars the objectives of postal censorship encompassed economic warfare and intelligence; the study of postal censorship is a philatelic topic of postal history. Military mail is not always censored by opening or reading the mail, but this is much more during wartime and military campaigns; the military postal service is separate from civilian mail and is totally controlled by the military.
However, both civilian and military mail can be of interest to military intelligence, which has different requirements from civilian intelligence gathering. During wartime, mail from the front is opened and offending parts blanked or cut out, civilian mail may be subject to much the same treatment. Prisoner-of-war and internee mail is subject to postal censorship, permitted under Articles 70 and 71 of the Third Geneva Convention, it is subjected to both military and civil postal censorship because it passes through both postal systems. Until recent years, the monopoly for carrying civilian mails has been vested in governments and this has facilitated their control of postal censorship; the type of information obtained from civilian mail is different from that to be found in military mail. Throughout modern history various governments during times of war, would inspect mail coming into or leaving the country so as to prevent an enemy from corresponding with unfriendly entities within that country.
There exist many examples of prisoner of war mail from these countries, inspected or censored. Censored mail can be identified by various postmarks, postage stamps and other markings found on the front and reverse side of the cover; these covers have an adhesive seal bearing special ID markings, which were applied to reclose and seal the envelope after inspection. During the years leading up to the American Revolution, the British monarchy in the American colonies manipulated the mail and newspapers sent between the various colonies in an effort to prevent them from being informed and from organizing with each other. Mail would be outright destroyed. During the American Civil War both the Union and Confederate governments enacted postal censorship; the number of Union and Confederate soldiers in prisoner of war camps would reach an astonishing one and a half million men. The prison population at the Andersonville Confederate POW camp alone reached 45,000 men by the war's end. There was much mail sent to and from soldiers held in POW installations.
Mail going to or leaving prison camps in the North and South was inspected both before and after delivery. Mail crossing enemy lines was only allowed at two specific locations. In Britain, the General Post Office was formed in 1657, soon evolved a "Secret Office" for the purpose of intercepting and deciphering coded correspondence from abroad; the existence of the Secret Office was made public in 1742 when it was found that in the preceding 10 years the sum of £45,675 had been secretly transferred from the Treasury to the General Post Office to fund the censorship activities. In 1782 responsibility for administering the Secret Office was transferred to the Foreign Secretary and it was abolished by Lord Palmerston in 1847. During the Second Boer War a well planned censorship was implemented by the British that left them well experienced when The Great War started less than two decades later. Offices were in Pretoria and Durban and throughout much of the Cape Colony as well a POW censorship with camps in Bloemfontein, St Helena, Ceylon and Bermuda.
The British Post Office Act 1908 allowed censorship upon issue of warrants by a secretary of state in both Great Britain and in the Channel Islands. During the Great War postal censorship occurred in Great Britain, France and other various countries involved with that war. Following the end of World War I there were some places. During 1919 it was operating in Austria, Canada, German Weimar Republic and the Soviet Union as well as other territories; the Irish Civil War saw mail raided by the IRA, marked as censored and sometimes opened in the newly independent state. The National Army opened mail and censorship of irregulars' mail in prisons took place. Other conflicts during which censorship existed included the Third Anglo-Afghan War, Chaco War, were the Italian occupation of Ethiopia and during the Spanish Civil War of 1936-1939. During World War II both the Allies and Axis instituted postal censorship of civil mail; the largest organisations were those of the United States, though the United Kingdom employed about 10,000 censor staff while Ireland, a small neutral country, only employed about 160 censors.
Both blacklists and whitelists were employed to observe suspicious mail or listed those whose mail was exempt from censorship. Bri
Cryptanalysis is the study of analyzing information systems in order to study the hidden aspects of the systems. Cryptanalysis is used to breach cryptographic security systems and gain access to the contents of encrypted messages if the cryptographic key is unknown. In addition to mathematical analysis of cryptographic algorithms, cryptanalysis includes the study of side-channel attacks that do not target weaknesses in the cryptographic algorithms themselves, but instead exploit weaknesses in their implementation. Though the goal has been the same, the methods and techniques of cryptanalysis have changed drastically through the history of cryptography, adapting to increasing cryptographic complexity, ranging from the pen-and-paper methods of the past, through machines like the British Bombes and Colossus computers at Bletchley Park in World War II, to the mathematically advanced computerized schemes of the present. Methods for breaking modern cryptosystems involve solving constructed problems in pure mathematics, the best-known being integer factorization.
Given some encrypted data, the goal of the cryptanalyst is to gain as much information as possible about the original, unencrypted data. It is useful to consider two aspects of achieving this; the first is breaking the system —, discovering how the encipherment process works. The second is solving the key, unique for a particular encrypted message or group of messages. Attacks can be classified based on; as a basic starting point it is assumed that, for the purposes of analysis, the general algorithm is known. This is a reasonable assumption in practice — throughout history, there are countless examples of secret algorithms falling into wider knowledge, variously through espionage and reverse engineering.: Ciphertext-only: the cryptanalyst has access only to a collection of ciphertexts or codetexts. Known-plaintext: the attacker has a set of ciphertexts to which he knows the corresponding plaintext. Chosen-plaintext: the attacker can obtain the ciphertexts corresponding to an arbitrary set of plaintexts of his own choosing.
Adaptive chosen-plaintext: like a chosen-plaintext attack, except the attacker can choose subsequent plaintexts based on information learned from previous encryptions. Adaptive chosen ciphertext attack. Related-key attack: Like a chosen-plaintext attack, except the attacker can obtain ciphertexts encrypted under two different keys; the keys are unknown. Attacks can be characterised by the resources they require; those resources include: Time -- the number of computation steps. Memory — the amount of storage required to perform the attack. Data — the quantity and type of plaintexts and ciphertexts required for a particular approach. It's sometimes difficult to predict these quantities especially when the attack isn't practical to implement for testing, but academic cryptanalysts tend to provide at least the estimated order of magnitude of their attacks' difficulty, for example, "SHA-1 collisions now 252."Bruce Schneier notes that computationally impractical attacks can be considered breaks: "Breaking a cipher means finding a weakness in the cipher that can be exploited with a complexity less than brute force.
Never mind that brute-force might require 2128 encryptions. The results of cryptanalysis can vary in usefulness. For example, cryptographer Lars Knudsen classified various types of attack on block ciphers according to the amount and quality of secret information, discovered: Total break — the attacker deduces the secret key. Global deduction — the attacker discovers a functionally equivalent algorithm for encryption and decryption, but without learning the key. Instance deduction — the attacker discovers additional plaintexts not known. Information deduction — the attacker gains some Shannon information about plaintexts not known. Distinguishing algorithm — the attacker can distinguish the cipher from a random permutation. Academic attacks are against weakened versions of a cryptosystem, such as a block cipher or hash function with some rounds removed. Many, but not all, attacks become exponentially more difficult to execute as rounds are added to a cryptosystem, so it's possible for the full cryptosystem to be strong though reduced-round variants are weak.
Nonetheless, partial breaks that come close to breaking the original cryptosystem may mean that a full break will follow. In academic cryptography, a weakness or a break in a scheme is defined quite conservatively: it might require impractical amounts of time, memory, or known plaintexts, it might require the attacker be able to do things many real-world attackers can't: for example, the attacker may need to choose particular plaintexts to be encrypted or to ask for plaintexts to be encrypted using several keys related to the secret key. Furthermore
In espionage and counterintelligence, surveillance is the monitoring of behavior, activities, or other changing information for the purpose of influencing, directing, or protecting people. This can include observation from a distance by means of electronic equipment or interception of electronically transmitted information, it can include simple no- or low-technology methods such as human intelligence agent and postal interception. The word surveillance comes from a French phrase for "watching over" and is in contrast to more recent developments such as sousveillance. Surveillance is used by governments for intelligence gathering, prevention of crime, the protection of a process, group or object, or the investigation of crime, it is used by criminal organisations to plan and commit crimes, such as robbery and kidnapping, by businesses to gather intelligence, by private investigators. Surveillance can be viewed as a violation of privacy, as such is opposed by various civil liberties groups and activists.
Liberal democracies have laws which restrict domestic government and private use of surveillance limiting it to circumstances where public safety is at risk. Authoritarian government have any domestic restrictions, international espionage is common among all types of countries; the area of surveillance is a topic of academic study, including through research centers and peer-reviewed academic journals. "In the future, intelligence services might use the internet of things for identification, monitoring, location tracking, targeting for recruitment, or to gain access to networks or user credentials," Clapper said. The vast majority of computer surveillance involves the monitoring of data and traffic on the Internet. In the United States for example, under the Communications Assistance For Law Enforcement Act, all phone calls and broadband Internet traffic are required to be available for unimpeded real-time monitoring by federal law enforcement agencies. There is far too much data on the Internet for human investigators to manually search through all of it.
Therefore, automated Internet surveillance computers sift through the vast amount of intercepted Internet traffic to identify and report to human investigators the traffic, considered interesting or suspicious. This process is regulated by targeting certain "trigger" words or phrases, visiting certain types of web sites, or communicating via email or online chat with suspicious individuals or groups. Billions of dollars per year are spent by agencies, such as the NSA, the FBI and the now-defunct Information Awareness Office, to develop, purchase and operate systems such as Carnivore, NarusInsight, ECHELON to intercept and analyze all of this data to only extract the information, useful to law enforcement and intelligence agencies. Computers can be a surveillance target because of the personal data stored on them. If someone is able to install software, such as the FBI's Magic Lantern and CIPAV, on a computer system, they can gain unauthorized access to this data; such software could be installed remotely.
Another form of computer surveillance, known as van Eck phreaking, involves reading electromagnetic emanations from computing devices in order to extract data from them at distances of hundreds of meters. The NSA runs a database known as "Pinwale", which stores and indexes large numbers of emails of both American citizens and foreigners. Additionally, the NSA runs a program known as PRISM, a data mining system that gives the United States government direct access to information from technology companies. Through accessing this information, the government is able to obtain search history, stored information, live chats, file transfers, more; this program generated huge controversies in regards to surveillance and privacy from U. S. citizens. The official and unofficial tapping of telephone lines is widespread. In the United States for instance, the Communications Assistance For Law Enforcement Act requires that all telephone and VoIP communications be available for real-time wiretapping by Federal law enforcement and intelligence agencies.
Two major telecommunications companies in the U. S.—AT&T Inc. and Verizon—have contracts with the FBI, requiring them to keep their phone call records searchable and accessible for Federal agencies, in return for $1.8 million per year. Between 2003 and 2005, the FBI sent out more than 140,000 "National Security Letters" ordering phone companies to hand over information about their customers' calling and Internet histories. About half of these letters requested information on U. S. citizens. Human agents are not required to monitor most calls. Speech-to-text software creates machine-readable text from intercepted audio, processed by automated call-analysis programs, such as those developed by agencies such as the Information Awareness Office, or companies such as Verint, Narus, which search for certain words or phrases, to decide whether to dedicate a human agent to the call. Law enforcement and intelligence services in the United Kingdom and the United States possess technology to activate the microphones in cell phones remotely, by accessing phones' diagnostic or maintenance features in order to listen to conversations that take place near the person who holds the phone.
The StingRay tracker is an example of one of these tools used to monitor cell phone usage in the United States and the United Kingdom. Developed for counterterrorism purposes by the military, they work by bro
Optical fiber cable
An optical fiber cable known as a fiber optic cable, is an assembly similar to an electrical cable, but containing one or more optical fibers that are used to carry light. The optical fiber elements are individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed. Different types of cable are used for different applications, for example long distance telecommunication, or providing a high-speed data connection between different parts of a building. Optical fiber consists of a core and a cladding layer, selected for total internal reflection due to the difference in the refractive index between the two. In practical fibers, the cladding is coated with a layer of acrylate polymer or polyimide; this coating protects the fiber from damage but does not contribute to its optical waveguide properties. Individual coated fibers have a tough resin buffer layer or core tube extruded around them to form the cable core. Several layers of protective sheathing, depending on the application, are added to form the cable.
Rigid fiber assemblies sometimes put light-absorbing glass between the fibers, to prevent light that leaks out of one fiber from entering another. This reduces flare in fiber bundle imaging applications. For indoor applications, the jacketed fiber is enclosed, with a bundle of flexible fibrous polymer strength members like aramid, in a lightweight plastic cover to form a simple cable; each end of the cable may be terminated with a specialized optical fiber connector to allow it to be connected and disconnected from transmitting and receiving equipment. For use in more strenuous environments, a much more robust cable construction is required. In loose-tube construction the fiber is laid helically into semi-rigid tubes, allowing the cable to stretch without stretching the fiber itself; this protects the fiber from tension during due to temperature changes. Loose-tube fiber may be gel-filled. Dry block offers less protection to the fibers than gel-filled, but costs less. Instead of a loose tube, the fiber may be embedded in a heavy polymer jacket called "tight buffer" construction.
Tight buffer cables are offered for a variety of applications, but the two most common are "Breakout" and "Distribution". Breakout cables contain a ripcord, two non-conductive dielectric strengthening members, an aramid yarn, 3 mm buffer tubing with an additional layer of Kevlar surrounding each fiber; the ripcord is a parallel cord of strong yarn, situated under the jacket of the cable for jacket removal. Distribution cables have an overall Kevlar wrapping, a ripcord, a 900 micrometer buffer coating surrounding each fiber; these fiber units are bundled with additional steel strength members, again with a helical twist to allow for stretching. A critical concern in outdoor cabling is to protect the fiber from contamination by water; this is accomplished by use of solid barriers such as copper tubes, water-repellent jelly or water-absorbing powder surrounding the fiber. The cable may be armored to protect it from environmental hazards, such as construction work or gnawing animals. Undersea cables are more armored in their near-shore portions to protect them from boat anchors, fishing gear, sharks, which may be attracted to the electrical power, carried to power amplifiers or repeaters in the cable.
Modern cables come in a wide variety of sheathings and armor, designed for applications such as direct burial in trenches, dual use as power lines, installation in conduit, lashing to aerial telephone poles, submarine installation, insertion in paved streets. In September 2012, NTT Japan demonstrated a single fiber cable, able to transfer 1 petabit per second over a distance of 50 kilometers. Modern fiber cables can contain up to a thousand fibers in a single cable, with potential bandwidth in the terabytes per second. In some cases, only a small fraction of the fibers in a cable may be "lit". Companies can lease or sell the unused fiber to other providers who are looking for service in or through an area. Companies may "overbuild" their networks for the specific purpose of having a large network of dark fiber for sale, reducing the overall need for trenching and municipal permitting, they may deliberately under-invest to prevent their rivals from profiting from their investment. The highest strand-count singlemode fiber cable manufactured is the 864-count, consisting of 36 ribbons each containing 24 strands of fiber.
Optical fibers are strong, but the strength is drastically reduced by unavoidable microscopic surface flaws inherent in the manufacturing process. The initial fiber strength, as well as its change with time, must be considered relative to the stress imposed on the fiber during handling and installation for a given set of environmental conditions. There are three basic scenarios that can lead to strength degradation and failure by inducing flaw growth: dynamic fatigue, static fatigues, zero-stress aging. Telcordia GR-20, Generic Requirements for Optical Fiber and Optical Fiber Cable, contains reliability and quality criteria to protect optical fiber in all operating conditions; the criteria concentrate on conditions in an outside plant environment. For the indoor plant, similar criteria are in Telcordia GR-409, Generic Requirements for Indoor Fiber Optic Cable. OFC: Optical fiber, conductive OFN: Optical fiber, nonconductive OFCG: Optical fiber, general use OFNG: Optical fiber, general use OFCP: Optical fiber, conductive
Secrecy of correspondence
The secrecy of correspondence or translated as secrecy of letters, is a fundamental legal principle enshrined in the constitutions of several European countries. It guarantees that the content of sealed letters is never revealed and letters in transit are not opened by government officials or any other third party, it is thus the main legal basis for the assumption of privacy of correspondence. The principle has been extended to other forms of communication, including telephony and electronic communications on the Internet as the constitutional guarantees are thought to cover these forms of communication. However, national telecommunications privacy laws may allow lawful interception, i.e. wiretapping and monitoring of electronic communications in cases of suspicion of crime. Paper letters have in most jurisdictions remained outside the legal scope of law enforcement surveillance in cases of "reasonable searches and seizures"; when applied to electronic communication, the principle protects not only the content of the communication, but the information on when and to whom any messages have been sent, in the case of mobile communication, the location information of the mobile units.
As a consequence, in jurisdictions with a safeguard on secrecy of letters, location data collected from mobile phone networks has a higher level of protection than data collected by vehicle telematics or transport tickets. In the United States there is no specific constitutional guarantee on the privacy of correspondence; the secrecy of letters and correspondence is derived through litigation from the Fourth Amendment to the United States Constitution. In an 1877 case the U. S. Supreme Court stated: No law of Congress can place in the hands of officials connected with the Postal Service any authority to invade the secrecy of letters and such sealed packages in the mail; the protection of the Fourth Amendment has been extended beyond the home in other instances. A protection similar to that of correspondence has been argued to extend to the contents of trash cans outside one's house, although unsuccessfully. Like all rights derived through litigation, the secrecy of correspondence is subject to interpretations.
By Supreme Court precedent, rights derived from the Fourth Amendment are limited by the legal test of a "reasonable expectation of privacy". Black room Data privacy Dead letter Electronic Communications Privacy Act Katz v. United States Lawful interception Postal censorship Telecommunications data retention Act on the Protection of Privacy at the Finnish Communications Regulatory Authority site Letter to the House On the Privacy of Outbound U. S. Mail by ACLU Anuj C. Desai; the Post Office and the Birth of Communications Privacy Back when spies played by the rules by David Kahn, New York Times - A history of the secrecy of letters
ECHELON a secret government code name, is a surveillance program operated by the US with the aid of four other signatory nations to the UKUSA Security Agreement: Australia, New Zealand and the United Kingdom known as the Five Eyes. The ECHELON program was created in the late 1960s to monitor the military and diplomatic communications of the Soviet Union and its Eastern Bloc allies during the Cold War, it was formally established in 1971. By the end of the 20th century, the system referred to as "ECHELON" had evolved beyond its military and diplomatic origins to become "…a global system for the interception of private and commercial communications"; the European Parliament's Temporary Committee on the ECHELON Interception System stated, "It seems in view of the evidence and the consistent pattern of statements from a wide range of individuals and organisations, including American sources, that its name is in fact ECHELON, although this is a minor detail". The U. S. intelligence community uses many code names.
Former NSA employee Margaret Newsham claims that she worked on the configuration and installation of software that makes up the ECHELON system while employed at Lockheed Martin, from 1974 to 1984 in Sunnyvale, California, in the United States, in Menwith Hill, England, in the UK. At that time, according to Newsham, the code name ECHELON was NSA's term for the computer network itself. Lockheed called it P415; the software programs were called SILKWORTH and SIRE. A satellite named VORTEX intercepted communications. An image available on the internet of a fragment torn from a job description shows Echelon listed along with several other code names. Britain's The Guardian newspaper summarized the capabilities of the ECHELON system as follows: A global network of electronic spy stations that can eavesdrop on telephones and computers, it can track bank accounts. This information is stored in Echelon computers. However, Echelon doesn't exist. In 1972, former NSA analyst Perry Fellwock, under pseudonym Winslow Peck, first blew the whistle on ECHELON to Ramparts in 1972, where he gave commentary revealing a global network of listening posts and his experiences working there.
Fellwock included revelations such as the existence of nuclear weapons in Israel in 1972, the widespread involvement of CIA and NSA personnel in drugs and human smuggling, CIA operatives leading Nationalist Chinese commandos in burning villages inside PRC borders. In 1982, James Bamford, investigative journalist and author wrote The Puzzle Palace, an in-depth look inside the workings of the NSA a super-secret agency, the massive eavesdropping operation under the codename "SHAMROCK"; the NSA has used many codenames, SHAMROCK was the code name used for ECHELON prior to 1975. In 1988, Margaret Newsham, a Lockheed employee under NSA contract, disclosed the ECHELON surveillance system to members of congress. Newsham told a member of the U. S. Congress that the telephone calls of Strom Thurmond, a Republican U. S. senator, were being collected by the NSA. Congressional investigators determined that "targeting of U. S. political figures would not occur by accident, but was designed into the system from the start."Also in 1988, an article titled "Somebody's Listening", written by investigative journalist Duncan Campbell in the New Statesman, described the signals intelligence gathering activities of a program code-named "ECHELON".
James Bamford describes the system as the software controlling the collection and distribution of civilian telecommunications traffic conveyed using communication satellites, with the collection being undertaken by ground stations located in the footprint of the downlink leg. A detailed description of ECHELON was provided by New Zealand journalist Nicky Hager in his 1996 book Secret Power: New Zealand's Role in the International Spy Network. Two years Hager's book was cited by the European Parliament in a report titled "An Appraisal of the Technology of Political Control". In March 1999, for the first time in history, the Australian government admitted that news reports about the top secret UKUSA Agreement were true. Martin Brady, the director of Australia's Defence Signals Directorate told the Australian broadcasting channel Nine Network that the DSD "does co-operate with counterpart signals intelligence organisations overseas under the UKUSA relationship."In 2000, James Woolsey, the former Director of the U.
S. Central Intelligence Agency, confirmed that U. S. intelligence uses keyword searches to monitor European businesses. Lawmakers in the United States feared that the ECHELON system could be used to monitor U. S. citizens. According to The New York Times, the ECHELON system has been "shrouded in such secrecy that its existence has been difficult to prove." Critics said the ECHELON system emerged from the Cold War as a "Big Brother without a cause". The program's capabilities and political implications were investigated by a committee of the European Parliament during 2000 and 2001 with a report published in 2001. In July 2000, the Temporary Committee on the ECHELON Interception System was established by the European parliament to investigate the surveillance network, it was chaired by the Portuguese politician Carlos Coelho, in charge of supervising investigations throughout 2000 and 2001. In May 2001, as the committee finalised its report on the ECHELON system, a delegation travelled to Washington, D.
C. to attend meetings with U. S. officials from the following agencies and departm
St Paul's Cathedral
St Paul's Cathedral, London, is an Anglican cathedral, the seat of the Bishop of London and the mother church of the Diocese of London. It is a Grade I listed building, its dedication to Paul the Apostle dates back to the original church on this site, founded in AD 604. The present cathedral, dating from the late 17th century, was designed in the English Baroque style by Sir Christopher Wren, its construction, completed in Wren's lifetime, was part of a major rebuilding programme in the City after the Great Fire of London. The cathedral building destroyed in the Great Fire, now referred to as Old St Paul's Cathedral, was a central focus for medieval and early modern London, including Paul's walk and St. Paul's Churchyard being the site of St. Paul's Cross; the cathedral is one of the most recognisable sights of London. Its dome, framed by the spires of Wren's City churches, has dominated the skyline for over 300 years. At 365 feet high, it was the tallest building in London from 1710 to 1967; the dome is among the highest in the world.
St Paul's is the second-largest church building in area in the United Kingdom after Liverpool Cathedral. Services held at St Paul's have included the funerals of Admiral Nelson, the Duke of Wellington, Sir Winston Churchill and Baroness Thatcher. St Paul's Cathedral is the central subject of much promotional material, as well as of images of the dome surrounded by the smoke and fire of the Blitz; the cathedral is a working church with daily services. The tourist entry fee at the door is £ 20 for adults. A list of the 16 "archbishops" of London was recorded by Jocelyn of Furness in the 12th century, claiming London's Christian community was founded in the 2nd century under the legendary King Lucius and his missionary saints Fagan, Deruvian and Medwin. None of, considered credible by modern historians but, although the surviving text is problematic, either Bishop Restitutus or Adelphius at the 314 Council of Arles seems to have come from Londinium; the location of Londinium's original cathedral is unknown.
Bede records that in AD 604 Augustine of Canterbury consecrated Mellitus as the first bishop to the Anglo-Saxon kingdom of the East Saxons and their king, Sæberht. Sæberht's uncle and overlord, Æthelberht, king of Kent, built a church dedicated to St Paul in London, as the seat of the new bishop, it is assumed, although not proved, that this first Anglo-Saxon cathedral stood on the same site as the medieval and the present cathedrals. On the death of Sæberht in about 616, his pagan sons expelled Mellitus from London, the East Saxons reverted to paganism; the fate of the first cathedral building is unknown. Christianity was restored among the East Saxons in the late 7th century and it is presumed that either the Anglo-Saxon cathedral was restored or a new building erected as the seat of bishops such as Cedd and Earconwald, the last of whom was buried in the cathedral in 693; this building, or a successor, was rebuilt in the same year. King Æthelred the Unready was buried in the cathedral on his death in 1016.
The cathedral was burnt, with much of the city, in a fire in 1087, as recorded in the Anglo-Saxon Chronicle. The present structure of St Peter upon Cornhill was designed by Christopher Wren following the Great Fire of London in 1666, it stands upon the highest point in the area of old Londinium, medieval legends tie it to the city's earliest Christian community. In 1995, however, a large and ornate 5th-century building on Tower Hill was excavated, which might have been the city's cathedral; the Elizabethan antiquarian William Camden argued that a temple to the goddess Diana had stood during Roman times on the site occupied by the medieval St Paul's Cathedral. Wren reported that he had found no trace of any such temple during the works to build the new cathedral after the Great Fire, Camden's hypothesis is no longer accepted by modern archaeologists; the fourth St Paul's referred to as Old St Paul's, was begun by the Normans after the 1087 fire. A further fire in 1136 disrupted the work, the new cathedral was not consecrated until 1240.
During the period of construction, the style of architecture had changed from Romanesque to Gothic and this was reflected in the pointed arches and larger windows of the upper parts and East End of the building. The Gothic ribbed vault was constructed, like that of York Minster, of wood rather than stone, which affected the ultimate fate of the building. An enlargement programme commenced in 1256. This'New Work' was consecrated in 1300 but not complete until 1314. During the Medieval period St Paul's was exceeded in length only by the Abbey Church of Cluny and in the height of its spire only by Lincoln Cathedral and St. Mary's Church, Stralsund. Excavations by Francis Penrose in 1878 showed that it was 100 feet wide; the spire was about 489 feet in height. By the 16th century the building was starting to decay. After the Protestant Reformation under Henry VIII and Edward VI, the Dissolution of the Monasteries and Chantries Acts led to the destruction of interior ornamentation and the cloisters, crypts, shrines and other buildings in St Paul's Churchyard.
Many of these former Catholic