Division of Altenburg

[2] The brothers had attempted to reconcile, but eventually the division led the Saxon Fratricidal War (German: Sächsischer Bruderkrieg),[3] which began in 1446 and lasted for five years, until the Peace of Naumburg was negotiated in 1451.

By the 15th century, the noble house of Wettin and its line of Upper Saxon princes had gained a large amount of land over the years mainly through inheritance, including the Margraviate of Meissen and the Duchy of Saxe-Wittenberg, which was elevated to the Electorate of Saxony according to the Golden Bull of 1356.

Upon the death of his younger brother William II in 1425, he ruled over all Wettin lands except for the Landgraviate of Thuringia, held by his cousin Frederick the Peaceful.

While Henry died in 1435 and Sigismund was forced to renounce his claims to become Bishop of Würzburg in 1440, only two sons, Frederick and William, now ruled over their family's land.

Following the multiple divisions and the Saxon Fratricidal War, the Wettins lost much of their power among the leading German noble families and houses,[5] most notably in favour of the rising Habsburg and Hohenzollern dynasties.