homage to the emperor. On the occasion, Otto the Great introduced his new daughter-in-law Theophanu, a Byzantine princess whose marriage to Otto II brought hope for recognition and continued peace between the rulers of the Eastern and Western empires. In 994, Otto III granted the right of market, tax, and coining, and established the first market place to the north of the castle hill. The town became a member of the Hanseatic League in 1426. Quedlinburg Abbey frequently disputed the independence of the town, which sought the aid of the Bishopric of Halberstadt. In 1477, Abbess Hedwig, aided by her brothers Ernest and Albert, broke the resistance of the town and expelled the bishop's forces. Quedlinburg was forced to leave the Hanseatic League and was subsequently protected by the Electorate of Saxony. Both town and abbey converted to Lutheranism in 1539 during the Protestant Reformation. In 1697, Elector Frederick Augustus I of Saxony sold his rights to Quedlinburg to Elector Frederick III of Brandenburg for 240,000 thalers. Quedlinburg Abbey contested Brandenburg-Prussia's claims throughout the 18th century, however. The abbey was secularized in 1802 during the German Mediatisation, and Quedlinburg passed to the Kingdom of Prussia as part of the Principality of Quedlinburg. Part of the Napoleonic Kingdom of Westphalia from 1807 to 1813, it was included within the new Prussian Province of Saxony in 1815. In all this time, ladies ruled Quedlinburg as abbesses without "taking the veil"; they were free to marry. The last of these ladies was a Swedish princess, an early fighter for women's rights, Sofia Albertina. During the Nazi regime, the memory of Henry I became a sort of cult, as Heinrich Himmler saw himself as the reincarnation of the "most German of all German" rulers. The collegiate church and castle were to be turned into a shrine for Nazi Germany. The Nazi Party tried to create a new religion. The cathedral was closed from 1938 and during the war. The local crematory was kept busy burning the victims of the Langenstein-Zwieberge concentration camp. Georg Ay was local party chief from 1931 until the end of the war. American occupation during the last months of World War II brought back the Protestant bishop and the church bells, and the Nazi-style eagle was removed from the tower. However, in the 1980s, upon the death of one of the US military men, the theft of medieval art from