The Ascanian line of Saxe-Wittenberg became extinct with the death of Elector Albert III in 1422, after which Emperor Sigismund granted the country and electoral privilege upon Margrave Frederick IV of Meissen, who had been a loyal supporter in the Hussite Wars. The late Albert's Ascanian relative, Duke Eric V of Saxe-Lauenburg protested in vain. Frederick, one of the seven Prince-electors, was a member of the House of Wettin, which since 1089 had ruled over the adjacent Margravate of Meissen up the Elbe river - established under Emperor Otto I in 965 - and also over the Landgravate of Thuringia since 1242. Thus, in 1423, Saxe-Wittenberg, the Margravate of Meissen and Thuringia were united under one ruler, and as a unified territory gradually became known as, "Upper Saxony".