The Tughlaq dynasty lasted from 1320 to nearly the end of 14th century. The first ruler Ghazi Malik rechristened himself as Ghiyas-ud-din Tughlaq and is also referred to in scholarly works as Tughlak Shah. He was of Turko-Indian origins, with a Turkic father and a Hindu mother. Ghiyasuddin Tughlaq ruled for five years and launched a town near Delhi named Tughlaqabad. According to some historians such as Vincent Smith, he was killed by his son Juna Khan, who then assumed power in 1325. Juna Khan rechristened himself as Muhammad bin Tughlaq and ruled for 26 years. During his rule, Delhi Sultanate reached its peak in terms of geographical reach, covering most of the Indian subcontinent.

    Muhammad bin Tughlaq was an intellectual, with extensive knowledge of the Quran, Fiqh, poetry and other fields. He was also deeply suspicious of his kinsmen and wazirs (ministers), extremely severe with his opponents, and took decisions that caused economic upheaval. For example, he ordered minting of coins from base metals with face value of silver coins – a decision that failed because ordinary people minted counterfeit coins from base metal they had in their houses and used them to pay taxes and jizya.

Muhammad bin Tughlaq moved his capital to the Deccan Plateau, ordered Delhi people to move and build a new capital named Daulatabad (shown), then reversed his decision because Daulatabad lacked the river and drinking water supply Delhi had.

A base metal coin of Muhammad bin Tughlaq that led to an economic collapse. On another occasion, after becoming upset by some accounts, or to run the Sultanate from the center of India by other accounts, Muhammad bin Tughlaq ordered the transfer of his capital from Delhi to Deogir in Maharashtra (renaming it to Daulatabad), by forcing mass migration of Delhi’s population. Those who refused were killed. One blind person who failed to move to Deogir was dragged for the entire journey of 40 days – the man died, his body fell apart, and only his tied leg reached Daulatabad. The capital move failed because Daulatabad was arid and did not have enough drinking water to support the new capital. The capital then returned to Delhi. Nevertheless, Muhammad bin Tughlaq’s orders affected history as a large number of Delhi Muslims who came to the Deccan area did not return to Delhi to live near Muhammad bin Tughlaq. This influx of the then-Delhi residents into the Deccan region led to a growth of Muslim population in central and southern India. Muhammad bin Tughlaq’s adventures in the Deccan region also marked campaigns of destruction and desecration of Hindu and Jain temples, for example the Svayambhu Shiva Temple and the Thousand Pillar Temple.

Revolts against Muhammad bin Tughlaq began in 1327, continued over his reign, and over time the geographical reach of the Sultanate shrunk. The Vijayanagara Empire originated in southern India as a direct response to attacks from the Delhi Sultanate. The Vijayanagara Empire liberated south India from the Delhi Sultanate rule.  In 1337, Muhammad bin Tughlaq ordered an attack on China, sending part of his forces over the Himalayas. Few survived the journey, and they were executed upon their return for failing.  During his reign, state revenues collapsed from his policies such as the base metal coins from 1329-1332. To cover state expenses, he sharply raised taxes. Those who failed to pay taxes were hunted and executed. Famines, widespread poverty, and rebellion grew across the kingdom. In 1338 his own nephew rebelled in Malwa, whom he attacked, caught, and flayed alive.[44] By 1339, the eastern regions under local Muslim governors and southern parts led by Hindu kings had revolted and declared independence from Delhi Sultanate. Muhammad bin Tughlaq did not have the resources or support to respond to the shrinking kingdom. The historian Walford chronicled Delhi and most of India faced severe famines during Muhammad bin Tughlaq’s rule in the years after the base metal coin experiment.  By 1347, Bahmani Sultanate had become an independent and competing Muslim kingdom in Deccan region of South Asia.

The Tughlaq dynasty is remembered for its architectural patronage, particularly for ancient lats (pillars, left image), dated to be from the 3rd century BC, and of Buddhist and Hindu origins. The Sultanate initially wanted to use the pillars to make Mosque minarets. Firoz Shah decided otherwise and had them installed near Mosques. The meaning of Brahmi script on the pillar at right was unknown in Firoz Shah’s time. The inscription was deciphered by James Prinsep in 1837; the pillar script of Emperor Ashoka asked people of his and future generations to seek adharmic (virtuous) life, use persuasion in religion, grant freedom from religious persecution, stop all killing, and be compassionate to all living beings.

Muhammad bin Tughlaq died in 1351 while trying to chase and punish people in Gujarat who were rebelling against Delhi Sultanate. He was succeeded by Firoz Shah Tughlaq (1351–1388), who tried to regain the old kingdom boundary by waging a war with Bengal for 11 months in 1359. However, Bengal did not fall, and it remained outside of Delhi Sultanate. Firoz Shah Tughlaq ruled for 37 years. His reign attempted to stabilize food supply and reduce famines by commissioning an irrigation canal from the Yamuna river. An educated sultan, Firoz Shah left a memoir. In it he wrote that he banned the practice of torture in Delhi Sultanate, such as amputations, tearing out of eyes, sawing people alive, crushing people’s bones as punishment, pouring molten lead into throats, setting people on fire, driving nails into hands and feet, among others. The Sunni Sultan also wrote that he did not tolerate attempts by Rawafiz Shia Muslim and Mahdi sects from proselytizing people into their faith, nor did he tolerate Hindus who tried to rebuild their temples after his armies had destroyed those temples.  As punishment, wrote the Sultan, he put many Shias, Mahdi, and Hindus to death (siyasat). Firoz Shah Tughlaq also lists his accomplishments to include converting Hindus to Sunni Islam by announcing an exemption from taxes and jizya for those who convert, and by lavishing new converts with presents and honours. Simultaneously, he raised taxes and jizya, assessing it at three levels, and stopping the practice of his predecessors who had historically exempted all Hindu Brahmins from jizya tax. He also vastly expanded the number of slaves in his service and those of amirs (Muslim nobles). The reign of Firoz Shah Tughlaq was marked by reduction in extreme forms of torture, eliminating favours to select parts of society, but also increased intolerance and persecution of targeted groups.

The death of Firoz Shah Tughlaq created anarchy and disintegration of the kingdom. The last rulers of this dynasty both called themselves Sultan from 1394 to 1397: Mahmud Tughlaq, the grandson of Firoz Shah Tughlaq who ruled from Delhi, and Nusrat Shah, another relative of Firoz Shah Tughlaq who ruled from Firozabad, which was a few miles from Delhi. The battle between the two relatives continued till the invasion by Timur in 1398. Timur, also known as Tamerlane in Western scholarly literature, was the Turkic Islamic king of Samarkand. He became aware of the weakness and quarreling of the Sultans in Delhi, so he marched with his army to Delhi, plundering and killing all the way.[61][62] Estimates for the massacre by Timur range from 100,000 to 200,000 people during his campaign. Timur had no intention of staying in or ruling India. He looted the lands he crossed, then plundered and burnt Delhi. Over five days, Timur and his Mongol army raged a massacre.[44] Then he collected and carried the wealth, captured women and slaves (particularly skilled artisans), and returned to Samarkand. The people and lands within Delhi Sultanate were left in a state of anarchy, chaos, and pestilence. Sultan Mahmud Tughlak, who had fled to Gujarat during Timur’s invasion, returned and nominally ruled as the last ruler of Tughlaq dynasty, as a puppet of various factions at the court.