second sultan of the Tughluq dynasty (reigned 1325–51), who briefly extended the rule of the Delhi sultanate of northern India over most of the subcontinent. As a result of misguided administrative actions and unexampled severity toward his opponents, he eventually lost his authority in the south; at the end of his reign, the sultanate had begun to decline in power.

Muḥammad was the son of the sultan Ghiyās-ud-Dīn Tughluq. Very little is known of his childhood, but he apparently received a good education. He possessed an encyclopaedic knowledge of the Qurʾān, Muslim jurisprudence, astronomy, logic, philosophy, medicine, and rhetoric. In 1321–22 his father sent him against the city of Warangal in the Deccan, in which campaign, after initial reverses, he subdued the rebellious Hindu rajas. From his accession to the throne in 1325 until his death in 1351, Muḥammad contended with 22 rebellions, pursuing his policies consistently and ruthlessly. Ziyāʾ-ud-Dīn Baranī (Baranī, Ẕiyāʾ al-Dīn), his close companion and counsellor for 17 years, often advised him to abdicate, but Muḥammad disdainfully rejected his advice.

As his reign began, Muḥammad attempted, without much success, to enlist the services of the ʿulamāʾ (ulama), the Muslim divines, and the Ṣūfīs, the ascetic mystics. Failing to win the ʿulamāʾ over, he tried to curtail their powers, as some of his predecessors had, by placing them on an equal footing with other citizens. The Sultan wanted to use the Ṣūfīs' prestigious position to stabilize his authority as ruler. Yet they had always refused any association with government and would not accept any grants or offices except under duress. Muḥammad tried every measure, conciliatory or coercive, to yoke them to his political wagon. Although he humiliated them, he could not break their opposition and succeeded only in dispersing them from the towns of northern India.

In the four pages of his so-called autobiography, Muḥammad's only surviving literary work, he confesses that he had wavered from traditional orthodoxy to philosophic doubts and then found his way to a rational faith. To still his own doubts, as well as to counteract the opposition of the Muslim divines, he obtained from the caliph in Cairo a manshūr (patent of royalty) legitimizing his authority.

The transfer of the capital in 1327 to Deogir (now Daulatābād (Daulatabad)) was intended to consolidate the conquests in southern India by large-scale, in some cases forced, migration of the people of Delhi to Deogir. As an administrative measure it failed, but it had far-reaching cultural effects. The spread of the Urdu language in the Deccan may be traced to this extensive influx of Muslims. He introduced several reforms in the monetary system, and his coins, in design as well as in workmanship and purity of metal, excelled those of his predecessors. His introduction of token currency, coins of baser metal with the face value of silver coins, however, failed dismally.

A projected Khorāsān expedition (1327–28) that never materialized was intended to secure more defensible frontiers in the west. The Karajil (Garhwal-Kumaon) expedition (1329–30), an attempt to adjust the boundary dispute with the northern hill states then dominated by China, ended in disaster, but it was followed by an exchange of emissaries between China and Delhi. The conquest of Nagarkot in the foothills of the Himalayas in northwestern India was based on Muḥammad's policy of establishing secure frontiers.

Between 1328 and 1329 the Sultan increased the land tax in the Doab—the land between the Ganges and Jumna rivers—but the taxpayers resisted it, especially because a severe drought coincided. Muḥammad was the first ruler to introduce rotation of crops, establish state farms, and tend cultivation and improve artificial irrigation by establishing a department of agriculture. When famine broke out in northern India (1338–40), he moved his residence to Swargdawari to supervise famine relief measures himself.

Muḥammad's last expedition, against the rebel Ṭaghī, ended with his death at Sonda in Sind in 1351. He died with a smile on his face and verses of his own composition on his lips. In the words of a contemporary, “the Sultan was rid of the people and the people of the Sultan.”

Sultan Muḥammad was among the most controversial and enigmatic figures of the 14th century. A dauntless soldier, he was tolerant in religion and was normally humane and humble, but these traits were vitiated at times by cruelty sometimes approaching the inhuman. He lived in constant conflict between faith and action, faith in the correctness of his policies and action in the means by which he sought to implement them. A born revolutionary, he desired to create a more equitable social order by making Islām a religion of service rather than a means of exploitation. This end, he believed, could be achieved only by a strong centralized authority based on justice and patronage of the poor, the learned, and the pious and on the suppression of rebellions mainly of the privileged classes in a tradition-ridden society.

All contemporary historians based their assessment of Muḥammad on his administrative measures, which were neither vicious nor visionary. They failed because of the harshness of the Sultan in executing them, the challenge they posed to the privileged classes, the general lethargy and conservatism of his subjects, and the expansion of the empire with which Muḥammad's administrative machinery could not cope.