On 24 February 1739 the army of Nader Shah, ruler of Iran, routed a much larger Mughal army at Karnal, north of Delhi. The Mughal emperor Muhammad Shah had dug in behind a fortified camp, but part of his army was drawn out onto the open plain and cut down by Persian musket and swivel-gun fire in a battle that lasted only a few hours. Nader was soon master of Delhi, and he left India with the Peacock Throne and the Koh-i-Noor diamond. Older accounts date the battle 13 February, which is the same day on the Julian calendar.
Nader Shah marches on India
Nader had seized the Iranian throne in 1736 after deposing the last Safavid boy-king. After invading Afghanistan in 1738 he advanced into the Mughal Empire, which Britannica describes as weakened by wars and internal strife since the death of Aurangzeb in 1707. He took Kabul, Peshawar and Lahore.1
In Delhi the court of Muhammad Shah reacted slowly. Britannica's biography calls him an ineffective, pleasure-seeking emperor whose provinces were already slipping out of his control. The Mughal army finally marched north and dug in at Karnal, on the old road from Delhi to Lahore, behind a canal, earthworks and its guns.2
Some accounts, such as Jadunath Sarkar's classic Nadir Shah in India, date the battle 13 February 1739. That is a date on the Julian calendar, which in 1739 ran eleven days behind the Gregorian, so it is the same day as 24 February, the date given by Britannica.3
Numbers on paper and in the field
The sizes of the armies are among the most uncertain figures of the period. Nader's secretary put the Mughal army at 300,000 men with 2,000 elephants and 3,000 guns. Sarkar, weighing the Indian and European accounts, thought the Mughal fighting force could not have been more than 75,000, with a crowd of servants and camp followers he guessed at a million people, and he accepted an estimate of about 55,000 Persian horsemen. All the sources agree that the Mughal host was far larger than Nader's.4
Nader's strength lay in discipline and firepower. His army included several thousand swivel-gunners whose discipline was strict: they held their fire until the word of command and then delivered a volley. His light swivel guns, the zamburaks, were carried on camels trained to lie down so that their backs served as a firing platform. Sarkar describes the Mughal guns, by contrast, as heavy, cumbersome and old-fashioned.5
A battle of a few hours
The battle began almost by accident. Saadat Khan, governor of Oudh, reached the Mughal camp with reinforcements during the night, and the next day Persian raiders fell on his baggage train. Against advice he rode out with only part of his men, chased Persian light horsemen who pretended to flee, and was drawn into an ambush far from the Mughal guns. Khan Dauran, the head of the Mughal army, followed with whatever troops he could gather.6
There the Persian musketeers and swivel guns opened fire at close range. The Mughal commanders, riding high on their elephants, made easy targets. Khan Dauran was mortally wounded, and Saadat Khan, whose elephant was driven into the Persian ranks, was captured. The rest of the Mughal army took no real part. Sarkar writes that the Nizam ul-Mulk, the ablest Mughal general, stayed idle all day, probably hoping to take his rivals' places at court if they fell.7
According to Nader's court historian, the fighting lasted less than three hours, from the midday prayer to the afternoon prayer, and Britannica says the Mughal lines began to fall apart after two hours. Khan Dauran died soon afterward. Britannica says the next day, while the sources Sarkar collected place his death anywhere from one to four days after the battle.8
Delhi and the Peacock Throne
Nader did not storm the fortified Mughal camp. He surrounded it, and within days Muhammad Shah came to the Persian camp and submitted. Nader then went on to Delhi. When a rumor spread that he had been killed, people in the city attacked his soldiers, and Nader answered by letting his troops plunder Delhi and massacre its inhabitants.9
The plunder was immense. It included the Peacock Throne and the Koh-i-Noor diamond, which Nader carried back to Iran. He left Muhammad Shah on the throne, but as his vassal. Britannica judges that Karnal marked the effective end of the Mughal Empire as a great power. The struggles for India that followed, from Plassey to the Third Battle of Panipat, are covered in our guide to the battles of India.10
The losses are disputed. Nader's court historian claimed 30,000 Indian dead, the Englishman Hanway, then in Persia, heard of 17,000, an Indian writer gave 20,000, and the Maratha envoy in the Mughal camp reported first 10,000 to 12,000 and later 7,000 to 8,000. Sarkar's own estimate was about 8,000. For the Persians, Hanway gave 2,500 killed and twice as many wounded.11
