Humayun was the second Mughal emperor who ruled from 1530 to 1540 and again from 1555 to 1556. His administration focused on reorganizing the government based on mystical principles by dividing public offices into elements of earth, fire, water, and air. Humayun participated in many wars but was unable to expand the empire significantly. During his reign, Islamic architecture flourished in India with the introduction of arches, domes, and decorative elements. Humayun died in 1556 after falling down the library stairs of his palace and hitting his head.