How long was the rule of Albert V of Austria
He was succeeded by his son Albert IV ( 1395–1404 ) and grandson Albert V ( 1404–1439 ) who regained the imperial throne for the Habsburgs and through his territorial acquisitions was set to become one of the most powerful rulers in Europe ( Beller p. 34 ) had he not died when he did , leaving only a posthumous heir , born four months later ( Ladislaus the Posthumous 1440–1457 ) .