After the death of Leopold's eldest son William in 1406, the Leopoldian line was further split among his brothers into the Inner Austrian territory under Ernest the Iron and a Tyrolean/Further Austrian line under Frederick of the empty pockets. In 1440, Ernest's son Frederick III was chosen by the electoral college to succeed Albert II as the king. Several Habsburg kings had attempted to gain the imperial dignity over the years, but success finally arrived on , when Pope Nicholas V crowned Frederick III as the Holy Roman Emperor in a grand ceremony held in Rome. In Frederick III, the Pope found an important political ally with whose help he was able to counter the conciliar movement.