after henry's death in 1435, and sigismund was forced to renounce and became a bishop in (1440), frederick and william divided their possessions. in the division of altenburg in 1445, william iii received the thuringian and frankish part, and frederick got the eastern part of the principality. the mines remained common possessions. disputes over the distribution led however in 1446 to the saxon brother war, which found an end only on 27 january 1451 with the peace of naumburg. in the treaty of eger in (1459), elector frederick, duke william iii and the king of bohemia george of podebrady fixed the borders between bohemia and saxony, at the height of the ore mountains () and the middle of the elbe which still holds today. it belongs therefore to the oldest still existing borders of europe.