Magdeburg (Low Saxon: Meideborg [ˈmaˑɪdebɔɐx]), the capital city of the Bundesland of Saxony-Anhalt, Germany, lies on the Elbe River and was one of the most important medieval cities of Europe. Emperor Otto I, the first Holy Roman Emperor, lived during most of his reign in the town and was buried in the cathedral after his death. Magdeburg's version of German town law, known as Magdeburg rights, spread throughout Central and Eastern Europe. The city is also well-known for the 1631 Sack of Magdeburg, which hardened Protestant resistance during the Thirty Years' War.