From The Anarchy: The East India Company, Corporate Violence, and the Pillage of an Empire, by William Dalrymple (Bloomsbury, 2019), Kindle pp. 76-80:
On 21 May, Nader Shah with a force of 80,000 fighting men crossed the border into the Mughal Empire, heading for the summer capital of Kabul, so beginning the first invasion of India for two centuries. The great Bala Hisar of Kabul surrendered at the end of June. Nader Shah then descended the Khyber. Less than three months later, at Karnal, one hundred miles north of Delhi, he defeated three merged Mughal armies – around a million men, some half of whom were fighters – with a relatively small but strictly disciplined force of 150,000 musketeers and Qizilbash horsemen armed with the latest military technology of the day: armour-penetrating, horse-mounted jazair, or swivel guns.
Nader Shah’s job was certainly made much easier by the increasingly bitter divisions between Muhammad Shah’s two principal generals, Sa’adat Khan and Nizam ul-Mulk. Sa’adat Khan arrived late at the Mughal camp, marching in from Avadh long after the Nizam had encamped, but, keen to show off his superior military abilities, decided to ride straight into battle without waiting for his exhausted soldiers to rest. Around noon on 13 February, he marched out of the earthwork defences erected by the Nizam to protect his troops, ‘with headlong impetuosity misplaced in a commander’, and against the advice of the Nizam, who remained behind, declaring that ‘haste is of the devil’. He was right to be cautious: Sa’adat Khan was walking straight into a carefully laid trap.
Nader Shah lured Sa’adat Khan’s old-fashioned heavy Mughal cavalry – armoured cuirassiers fighting with long swords – into making a massed frontal charge. As they neared the Persian lines, Nader’s light cavalry parted like a curtain, leaving the Mughals facing a long line of mounted musketeers, each of whom was armed with swivel guns. They fired at point-blank range. Within a few minutes, the flower of Mughal chivalry lay dead on the ground. As a Kashmiri observer, Abdul Karim Sharistani, put it, ‘the army of Hindustan fought with bravery. But one cannot fight musket balls with arrows.’
Having defeated the Mughals in an initial engagement, Nader Shah then managed to capture the Emperor himself by the simple ruse of inviting him to dinner, then refusing to let him leave. ‘Here was an army of a million bold and well-equipped horsemen, held as it were in captivity, and all the resources of the Emperor and his grandees at the disposal of the Persians,’ wrote Anand Ram Mukhlis. ‘The Mughal monarchy appeared to be at an end.’ ...
On 29 March, a week after Nader Shah’s forces had entered the Mughal capital, a newswriter for the Dutch VOC sent a report in which he described Nader Shah’s bloody massacre of the people of Delhi: ‘the Iranians have behaved like animals,’ he wrote. ‘At least 100,000 people were killed. Nader Shah gave orders to kill anyone who defended himself. As a result it seemed as if it were raining blood, for the drains were streaming with it.’ Ghulam Hussain Khan recorded how, ‘In an instant the soldiers getting on the tops of the houses commenced killing, slaughtering and plundering people’s property, and carrying away their wives and daughters. Numbers of houses were set on fire and ruined.’ ...
The massacre continued until the Nizam went bareheaded, his hands tied with his turban, and begged Nader on his knees to spare the inhabitants and instead to take revenge on him. Nader Shah ordered his troops to stop the killing; they obeyed immediately. He did so, however, on the condition that the Nizam would give him 100 crore (1 billion) rupees before he would agree to leave Delhi. ‘The robbing, torture and plundering still continues,’ noted a Dutch observer, ‘but not, thankfully, the killing.’
In the days that followed, the Nizam found himself in the unhappy position of having to loot his own city to pay the promised indemnity. The city was divided into five blocks and vast sums were demanded of each: ‘Now commenced the work of spoliation,’ remarked Anand Ram Mukhlis, ‘watered by the tears of the people … Not only was their money taken, but whole families were ruined. Many swallowed poison, and others ended their days with the stab of a knife … In short the accumulated wealth of 348 years changed masters in a moment.’
Nader never wished to rule India, just to plunder it for resources to fight his real enemies, the Russians and the Ottomans. Fifty-seven days later, he returned to Persia carrying the pick of the treasures the Mughal Empire had amassed over its 200 years of sovereignty and conquest: a caravan of riches that included Jahangir’s magnificent Peacock Throne, embedded in which was both the Koh-i-Noor diamond and the great Timur ruby. Nader Shah also took with him the Great Mughal Diamond, reputedly the largest in the world, along with the Koh-i-Noor’s slightly larger, pinker ‘sister’, the Daria-i-Noor, and ‘700 elephants, 4,000 camels and 12,000 horses carrying wagons all laden with gold, silver and precious stones’, worth in total an estimated £87.5 million in the currency of the time. In a single swift blow, Nader Shah had broken the Mughal spell. Muhammad Shah Rangila remained on the throne, but, with little remaining credibility or real power, he withdrew from public life, hardly leaving Delhi.