In 1407, however, conflicts between Leopold and Ernest resulted in a civil war that lasted until May 1409. When Leopold died without male heirs in 1411, Ernest finally became the uncontested head of the Leopoldian branch. In 1414, he became the last Duke to be enthroned according to Carantanian traditional rite at the Prince's Stone in Carinthia, and from that time on called himself 'archduke'. He was the first Habsburg to actually use this title, which had been invented by his uncle Duke Rudolf IV.