Short answers, pulled from the story.
An administrative decree dated the 31st of January 1772 designated former Ducal Prussia together with Warmia as the Province of East Prussia. King Frederick the Great annexed neighboring Royal Prussia during the First Partition of Poland in 1772 to connect his lands with Farther Pomeranian territories.
Duke Konrad I of Masovia invited the Teutonic Knights to conquer the native Old Prussians in the 13th century. These crusading orders established a monastic state to administer the conquered lands along the southeastern Baltic Coast.
Following Nazi Germany's defeat, East Prussia was partitioned between Poland and the Soviet Union according to the Potsdam Conference. Southern East Prussia was placed under Polish administration while northern parts were divided between Russia and Lithuania.
An estimated 300,000 people died from bombing raids battles mistreatment hunger cold or disease during the war. The medieval city of Königsberg was almost completely destroyed by two RAF Bomber Command raids on the night of the 26th of August 1944 and overnight on the 30th of August 1944.
Erich Koch headed the East Prussian Nazi party from 1928 and led the district from 1932. He implemented policies that included mass-scale industrialization plans which provoked conflict with Richard Walther Darré who wanted to enforce his vision of an agricultural East Prussia.