The Cloaca Maxima was one of the world's earliest sewage systems. Its name is related to that of Cloacina, a Roman goddess. Built during either the Roman Kingdom or early Roman Republic, it was constructed in Ancient Rome in order to drain local marshes and remove waste from the city. It carried effluent to the River Tiber, which ran beside the city. The sewer started at the Forum Augustum and ended at the Ponte Rotto and Ponte Palatino. It began as an open air canal, but it developed into a much larger sewer over the course of time. Agrippa renovated and reconstructed much of the sewer. This would not be the only development in the sewers. By the first century CE all eleven Roman aqueducts were connected to the sewer. After the Roman Empire fell the sewer still was used. By the 19th century, it became a tourist attraction. Some parts of the sewer are still used today. Whilst still being used, it was highly valued as a sacred symbol of Roman culture, and Roman engineering.

The Roman Kingdom, also referred to as the Roman monarchy or the regal period of ancient Rome, was the earliest period of Roman history when the city and its territory were ruled by kings. According to tradition, the Roman Kingdom began with the city's founding c. 753 BC, with settlements around the Palatine Hill along the river Tiber in central Italy, and ended with the overthrow of the kings and the establishment of the Republic c. 509 BC.