The Prussian Eastern Railway was a railway in the Kingdom of Prussia and later Germany until 1918. Its main route, approximately 740 kilometers (460 mi) long, connected the capital, Berlin, with the cities of Danzig and Königsberg. At Eydtkuhnen it reached the German Empire's border with the Russian Empire. The first part of the line opened in 1851, reaching Eydtkuhnen in 1860. By March 1880 the total route length reached 2,210 kilometers (1,370 mi), with a main parallel route in the south via Bromberg and Thorn to Insterburg. The lines were the first part of the later Prussian State Railways.

Königsberg is the historic German and Prussian name of the medieval city that is now Kaliningrad, Russia. The city was founded in 1255 on the site of the small Old Prussian settlement Twangste by the Teutonic Knights during the Baltic Crusades. It was named in honour of King Ottokar II of Bohemia, who led a campaign against the pagan Old Prussians, a Baltic tribe.