Karnal Battle, 1739: The 3-Hour War That Marked the Decline of the Mughal Empire and the Loss of the Kohinoor

On this day 287 years ago, February 24, 1739, the historic Battle of Karnal was fought—a conflict that would accelerate the decline of the Mughal Empire and lead to the plunder of India’s legendary Kohinoor diamond.

Karnal: A City Steeped in History

Karnal, located in present-day Haryana, roughly 110 km from Delhi between Panipat and Kurukshetra, was historically known as Karnatal. According to local legend, it was established by the famed Mahabharata king Karna, who built a tank (lake) here for ritual bathing and worship of the Sun.

Why the Battle Took Place

The Battle of Karnal was fought between Mughal Emperor Muhammad Shah and Persian King Nader Shah. After emerging victorious in the Battle of Damghan in 1729, Nader Shah consolidated power in Persia and became king in 1736. By 1738, he had invaded Afghanistan, capturing Kabul and Lahore. Seeing the Mughal Empire weakened after Emperor Aurangzeb’s death, Nader Shah advanced into India, confronting the Mughal army near Karnal.

A Three-Hour Defeat

Despite the Mughal army’s size—estimated at 300,000 soldiers, war elephants, and artillery spread over 3 km—internal disorganization and lack of strategy led to a swift defeat. Nader Shah’s 50,000-strong, well-coordinated army, equipped with modern weapons for the era, waited for the Mughal forces to approach and then unleashed a barrage of artillery.

According to Britannica, Mughal commanders fell quickly: one was captured and another killed after his war elephant was brought down. Within three hours, the massive Mughal army was shattered, many soldiers fled, and Nader Shah took control of Karnal and its ruler, Muhammad Shah, without significant resistance.

March to Delhi and Loot of Kohinoor

Nader Shah did not stop at Karnal. He advanced to Delhi, unleashing widespread massacre and plunder. Among the treasures seized were Shah Jahan’s famed peacock throne, encrusted with gold and gems, and the priceless Kohinoor diamond. Historical accounts, including those by N.B. Sen, trace the Kohinoor from Babur to Shah Jahan, then Aurangzeb, Sultan Mahmud, and finally looted by Nader Shah, who took it to Persia. He was assassinated eight years later.

Impact on the Mughal Empire

The Mughal Empire had already been weakening after Aurangzeb’s death in 1707, as successive emperors focused on luxury rather than warfare. The Battle of Karnal marked a critical turning point, accelerating the empire’s economic decline and paving the way for the rise of regional powers like the Bengal Nawabs, Awadh, Hyderabad, Marathas, and Sikhs. Within a few decades, the fragmented Mughal state became vulnerable to European colonial powers, ultimately enabling British dominance in India.