The history of Prussia was, from 1618 onwards, closely tied to that of the Margraviate of Brandenburg; the ruler of Prussia was also Elector of Brandenburg from 1618 to 1806. For a list of earlier rulers of Brandenburg, see Rulers of Brandenburg.
Following the death of Albert Frederick in 1618, the rule of the Duchy of Prussia passed to his son-in-law and distant cousin the Elector John Sigismund, who belonged to the senior branch of the Hohenzollern dynasty that ruled the Margraviate of Brandenburg. Though Margraviate and Duchy remained legally distinct, the combined lands are sometimes known as Brandenburg-Prussia.
Son of George William. In 1657, Frederick William obtained from the King of Poland recognition of his complete sovereignty over the Duchy of Prussia, which thereby became an independent state, though Poland retained the right of reversion should the Hohenzollern dynasty die out. The relative rights of the Duke of Prussia and the King of Poland were established in a series of treaties that were renewed on each change of ruler, down to 1698 (accession of Augustus II of Poland).
Son of Frederick William. In 1701 he was crowned "King in Prussia", marking the complete independence of Prussia from all Polish ties, but limiting his sovereignty to the former territory of Ducal Prussia.
Son of Frederick I. Known as "the soldier king" (German: Der Soldatenkönig). Reformed the army and limited the state expenditure not related to the armed forces.
Consequent on his annexation of Royal Prussia in the 1772 partition of Poland, Frederick the Great changed his title to "King of Prussia" rather than "King in Prussia".
Son of Frederick William II. With the dissolution of the Holy Roman Empire in 1806, he lost the title of Elector of Brandenburg, but was able to incorporate his territories in Brandenburg into the Kingdom of Prussia. Despite losses in the Napoleonic wars, at the Congress of Vienna Prussia's territory in Germany was greatly increased, making it the dominant power of northern Germany.
Son of preceding. The defeat of Germany in the First World War (1914) led William's abdication and exile and the fall of the House of Hohenzollern from power.
Although the German Empire no longer existed as a monarchy, its constituent states continued to exist as republics within the Weimar Republic. The Prussia was known as the Free State of Prussia.
Prime Ministers of the Free State of Prussia, 1918-1945
In 1932, the German Chancellor, Franz von Papen, overthrew the Prussian government in the Preußenschlag. Subsequently, Prussia was governed by a Reichskommissar:
Franz von Papen (no party) 1932 (German Chancellor and Reichskommissar)
Kurt von Schleicher (no party) 1932-1933 (German Chancellor and Reichskommissar)
Franz von Papen (no party) 1933 (German Vice-Chancellor and Reichskommissar)
After the seizure of power by the Nazis, a new Prime Minister was elected. However, this was largely a ceremonial role as the German states lost their power and became mere administrative units.
After the defeat of Nazi Germany in 1945, Prussia's provinces (sometimes in combination with non-Prussian territory) were reorganized into Länder. The state of Prussia was officially disbanded in 1947. The original Prussia was divided between Poland and the Soviet Union.
Pretenders to the Prussian throne
Hohenzollern Pretenders to the Prussian and German throne
