East Prussia (German: Ostpreußen, pronounced [ˈɔstˌpʁɔʏsən]); Polish: Prusy Wschodnie; Lithuanian: Rytų Prūsija or Rytprūsiai; Russian: Восточная Пруссия or Vostochnaya Prussiya) is the main part of the region of Prussia along the southeastern Baltic Coast from the 13th century to the end of World War II in May 1945. From 1772–1829 and 1878–1945, the Province of East Prussia was part of the German state of Prussia. The capital city was Königsberg.
East Prussia consist most of lands of the racially Baltic Old Prussian tribes. The native Prussians were brutally conquered by the crusading Teutonic Knights during the 13th century. The conquest of Prussia was accomplished with much bloodshed over more than 50 years, during which native Prussians who remained unbaptized were subjugated, killed, or exiled. Fighting between the Knights and the Prussians was ferocious; chronicles of the Order state the Prussians would
"roast captured brethren alive in their armour, like chestnuts, before the shrine of a local god".
The indigenous Balts were gradually converted to Christianity, but because of Germanization and colonisation over the following centuries, Germans became the dominant ethnic group, while Poles and Lithuanians formed the minorities.
From the 13th century, East Prussia was part of the monastic state of the Teutonic Knights, which became the Duchy of Prussia in 1525.
The Old Prussian language had become extinct by the 17th or early 18th century, by which the territory had become the Province of East Prussia.