Nasir al-Din Muhammad Humayun (1508 – 1556) was the second emperor of the Mughal Empire, who ruled what is today Afghanistan, Pakistan, and parts of northern India from 1531 to 1540 when he lost his dominions to a Pashtun noble. He regained them 15 years later with aid from the Persian Safavids, and ruled from 1555 to his death the following year, reestablishing the Mughal dynasty and passing its throne on to his son Akbar the Great.
The son and successor of Babur, founder of the Mughal Empire, Humayun inherited a restless realm, with many subjects – most notably the Afghans and Rajputs – not yet fully on board and reconciled to Mughal supremacy. He spent his first 9 years on the throne shuttling from one end of his realm to another, putting down revolts and fighting off intrigues, until 1540, when an Afghan adventurer with a power base in Bengal, Sher Shah, defeated Humayun and chased him out of India, while the rest of his realm rose up in revolt and threw off Mughal rule.
The former emperor hit the road, becoming a homeless wanderer, until he finally reached Persia in 1544, and succeeded in convincing its Shah to give him military aid. With Persian aid, Humayun set out to regain Afghanistan, and after 6 years of protracted campaigning, including the seizure of Kabul three times from a disloyal brother who had turned on him, he completed the task in 1550.
By 1555, back in India, Sher Shah had died and a civil war had broken out between his descendants. Seizing the opportunity, Humayun invaded what is now Pakistan, and captured Lahore, then plunged into and seized Punjab. Continuing his march, by July of 1555, Humayun had regained Delhi and Agra as well, and finally completed the restoration of the realm he had lost a decade and a half earlier.
He did not enjoy it for long, however. Only half a year after regaining his throne, on January 27th, 1556, Humayun was walking down the stairs from his library with his arms full of books when he heard a nearby mosque’s azan, or call to prayer. For some reason, he chose to pray then and there on the stairs, and when he knelt during the ritual, he got his foot tangled in his robe, tripped, and tumbled down the flight of steps to the stone ground below. He struck his head and died of his injuries three days later.