Saxon Fratricidal War The Saxon Fratricidal War ( German : " Sächsischer Bruderkrieg " ) was a war fought between the two brothers Frederick II , Elector of Saxony and Duke William III over Wettin ruled areas from 1446 to 1451 . After a dispute over the division of certain family lands between Frederick II and William III , the Division of Altenburg eventually led to growing tensions between the two brothers and an inability to agree on who ruled which areas . After failed attempts at reconciliation , the war broke out and lasted for five years . The war was destructive and had no clear winner before being ended with a peace treaty at Naumburg . Following the war and subsequent divisions the Saxons lost much of their former power and influence within the different German states and families . Background . The House of Wettin and its line of Saxon princes gained a large amount of land over the years mainly through inheritance , including the Landgraviate of Thuringia , the Margraviate of Meissen , the Duchy of Saxony and the Electorate of Saxony . Frederick I was the Elector of Saxony and Margrave of Meissen and ruled over all of the lands except for the lands in Thuringia . Frederick I ' s cousin Frederick of Thuringia was Landgrave of Thuringia and ruled over those lands . When Frederick I died in 1428 , his four sons Frederick II , Sigismund , Heinrich , and William III inherited his lands jointly . Heinrich died in 1435 , and in 1440 Sigmisund became Bishop of Würzburg and renounced his claims to the land . Frederick , who was the eldest of the two remaining sons , now held the Electorate of Saxony and some land around Wittenberg in his own right , whilst throughout the remainder of the land he ruled together with William . This continued without serious incident for twelve years until , in 1440 , Frederick of Thuringia died childless , and the two brothers inherited extensive land within Thuringia as well as the title of Landgrave of Thuringia . The division of this new land in Thuringia could not be agreed upon , and on 16 July 1445 the two remaining brothers tried to partition the land between them in the Division of Altenburg . When Frederick II chose the western part and not the Margraviate of Meissen on September 26 , 1445 in Leipzig , William rejected the division . On December 11 of the same year they attempted to reconcile in the monastery of Neuwerk in Halle ( Saale ) in what was known as the " Hallescher Machtspruch " ( English : the Power Dictum of Halle ) . The Archbishop of Magdeburg Frederick III of Beichlingen , the Margrave Frederick II of Brandenburg and the Landgrave Ludwig II of Hesse actively participated as judges , however the two brothers failed to reach a peaceful resolution . War . War first broke out between Frederick II and William III in 1446 when they were unable to resolve their dispute . Frederick proved stronger , and William brought in forces from Bohemia , including Hussites . Frederick ' s forces were led by commanders such as Kunz von Kaufungen , a captain from the tower of Kaufungen located near modern day Limbach - Oberfrohna . Frederick ' s forces under the command of Kunz won a victory at Gera and occupied the small town , however William ' s forces and Bohemian allies caused a large amount of damage to locations within Kaufungen in return . Kunz himself had much of his property destroyed and was taken captive by Bohemians . Eventually he paid the sum of 4 , 000 golden gulden for his freedom , which was very extravagant for the time . No side could gain a clear advantage throughout the war and the fighting turned out to be an extended period of " ruinous confusion " for the region . The war lasted five years and ended on January 27 , 1451 when a peace was reached at Naumburg . This peace could not reestablish a joint rule , but let the two sides accept a peaceful division of the lands . Aftermath . After the war , Kunz von Kaufungen expected to be repaid by Frederick II for the massive losses of his property during the fighting . Frederick also had losses of his own and therefore followed the letter of his contract with Kunz and did not even repay the ransom Kunz paid to the Bohemians . Frederick stated that Kunz was just his hired soldier , and he was not bound to protect him or repay his losses . Frederick eventually agreed upon bringing in arbitrators to settle the case , but Kunz left the arbitration before hearing the verdict when he realized it would not reach his expectations . Kunz continued to complain and insult Frederick until Frederick banished him from the lands . Kunz left to Bohemia and lived in the castle of Isenburg . Kunz eventually kidnapped Frederick ' s two sons , Ernest and Albert , from the castle of Altenburg in what was called the " Prinzenraub " ( English : " The stealing of the princes " ) . Prince Albert was found that very night when Kunz was caught , while Prince Ernst was released four days later when Kunz ' s allies released him for a pardon . On July 14 , 1455 , Kunz von Kaufungen was beheaded by order of Frederick at Freiberg . The lands fought over during the war were ruled peacefully again , however this time separately instead of jointly . Eventually , Frederick II died , and his two sons Ernest and Albert inherited his lands jointly in 1464 . When William III died in 1482 , without any sons , they inherited his lands and split them between them by the Treaty of Leipzig in 1485 . The division of these lands and this war led to the Saxons losing a large amount of influence within the different German states and no longer being one of the most powerful German houses .