Duchy of Prussia

Duchy of Prussia Herzogtum Preußen (German) Prusy Książęce (Polish) Prūsijos kunigaikštystė (Lithuanian)
1525–1701
Flag (1525–1657) Coat of arms
The Duchy of Prussia (yellow)
Status	Fief of Poland (until 1657) Part of Brandenburg-Prussia (from 1618)
Capital	Königsberg 54°50′N 21°20′E / 54.833°N 21.333°E / 54.833; 21.333
Common languages	Low German, German, Polish, Lithuanian,Old Prussian
Religion	Lutheranism[1]
Demonym(s)	Prussian
Government	Feudal monarchy
Duke
• 1525–1568	Albert
• 1568–1618	Albert Frederick
• 1618–1619	John Sigismund
• 1619–1640	George William
• 1640–1688	Frederick William
• 1688–1701	Frederick
Legislature	Estates
Historical era	Early modern period
• Prussian Homage	10 April 1525
• Treaty of Wehlau	1657
• Coronation	1701
Area
• Total	30,000 km2 (12,000 sq mi)
Currency	Thaler (1525-1701)
Preceded by Succeeded by State of the Teutonic Order Kingdom of Prussia Brandenburg-Prussia
Today part of	Lithuania Poland Russia

The Duchy of Prussia (German: Herzogtum Preußen, Polish: Księstwo Pruskie, Lithuanian: Prūsijos kunigaikštystė) or Ducal Prussia (German: Herzogliches Preußen; Polish: Prusy Książęce) was a duchy in the region of Prussia established as a result of secularization of the Monastic Prussia, the territory that remained under the control of the State of the Teutonic Order until the Protestant Reformation in 1525.