Polish–Lithuanian Commonwealth
The Polish–Lithuanian Commonwealth, formally known as the Kingdom of Poland and the Grand Duchy of Lithuania, or simply Poland–Lithuania, was a bi-confederal state, sometimes called a federation, of Poland and Lithuania ruled by a common monarch in real union, who was both King of Poland and Grand Duke of Lithuania. It was one of the largest and most populous countries of 16th- to 17th-century Europe. At its largest territorial extent, in the early 17th century, the Commonwealth covered almost 1,000,000 km2 (400,000 sq mi) and as of 1618 sustained a multi-ethnic population of almost 12 million. Polish and Latin were the two co-official languages, and Roman Catholicism served as the state religion.
The Union of Lublin joined the Kingdom of Poland and the Grand Duchy of Lithuania in 1569.
Sigismund III Vasa, who reigned between 1587 and 1632, presided over an era of prosperity and territorial expansion of the Commonwealth.
Sejm (parliament) of the Polish–Lithuanian Commonwealth in the early 17th century
John III Sobieski, victor over the Ottoman Turks at the Battle of Vienna in 1683.
A confederation is a political union of sovereign states united for purposes of common action. Usually created by a treaty, confederations of states tend to be established for dealing with critical issues, such as defence, foreign relations, internal trade or currency, with the central government being required to provide support for all its members. Confederalism represents a main form of intergovernmentalism, defined as any form of interaction around states that takes place on the basis of sovereign independence or government.
Proclamation of Canadian Confederation