The Division of Altenburg (German: Altenburger Teilung) was the plan for the division of the Meissen lands agreed upon by the two hostile Wettin brothers Elector Frederick II of Saxony and William III on 16 July 1445 at Altenburg. The brothers had attempted to reconcile, but eventually the division led the Saxon Fratricidal War (German: Sächsischer Bruderkrieg), which began in 1446 and lasted for five years, until the Peace of Naumburg was negotiated in 1451. Following the peace, the subsequent Treaty of Eger in 1459, and the deaths of Frederick II and Wilhelm III, the two sons of Frederick II eventually gained control of the land of both their father and William III.