 Archchancellor); however, his attempts failed as the elevation was rejected by the Luxembourg emperor Charles IV.By the 1379 Treaty of Neuberg, his heirs divided the Habsburg lands, whereafter the Austrian duchy remained under the rule of the Albertinian line.On Epiphany 1453 Emperor Frederick III, regent of Austria for his minor Albertinian cousin Ladislaus the Posthumous, finally acknowledged the archducal title.