On 24 January 1556, Humayun, with his arms full of books, was descending the staircase from his library Sher Mandal when the muezzin announced the Azaan (the call to prayer). It was his habit, wherever and whenever he heard the summons, to bow his knee in holy reverence. Trying to kneel, he caught his foot in his robe, slipped down several steps and hit his temple on a rugged stone edge. He died three days later.[51] His body was laid to rest in Purana Quila initially, but, because of an attack by Hemu on Delhi and the capture of Purana Qila, Humayun’s body was exhumed by the fleeing army and transferred to Kalanaur in Punjab where Akbar was crowned. After young Mughal emperor Akbar defeated and killed Hemu in the Second Battle of Panipat. Humayun’s body was buried in Humayun’s Tomb in Delhi the first very grand garden tomb in Mughal architecture, setting the precedent later followed by the Taj Mahal and many other Indian monuments. It was commissioned by his favorite and devoted chief wife, Bega Begum.