The Free Hanseatic City of Bremen is the smallest of Germany's 16 states. A more informal name, but used in some official contexts, is Land Bremen ('State of Bremen').
The state consists of two cities (Bremen and Bremerhaven) in the North of Germany, separated from each other and surrounded by the larger state of Lower Saxony.
At the unwinding of the Holy Roman Empire in 1806 the Free Imperial City of Bremen (as of 1646, after earlier privileges of autonomy of 1186) was not mediatised but became a sovereign state officially titled Free Hanseatic City of Bremen. Its currency was the Bremen thaler (until 1873). In 1811 the First French Empire annexed the city-state. Upon the first, albeit only preliminary, defeat of Napoléon Bonaparte, Bremen resumed its pre-1811 status as city-state in 1813.
The Vienna Congress of 1815 confirmed Bremen's—as well as Frankfurt's, Hamburg's, and Lübeck's—independence after pressuring by Bremen's emissary, and later burgomaster, Johann Smidt. Bremen became one of 39 sovereign states of the German Confederation. In 1827 the state of Bremen bought the tract of land from the Kingdom of Hanover, where future Bremerhaven would be established. Bremen became part of the North German Confederation in 1867 and became an autonomous component state of the new-founded German Empire in 1871 and stayed with Germany in its following forms of government.
Bremen, which in 1935 had become a regular city at the de facto abolition of statehood of all component German states within the Third Reich, was reestablished as state in 1947. Being—at that time—actually located in the British Zone of Occupation the Control Commission for Germany - British Element and the Office of Military Government for Germany, U.S. (OMGUS) agreed in 1947 to constitute the cities of Bremen and then Wesermünde—in their borders altered in 1939—as a German state named again Free Hanseatic City of Bremen, becoming at that occasion an exclave of the American Zone of Occupation within the British zone. In 1949 the city-state joined the then West German Federal Republic of Germany.