The victory was made possible by the defection of Mir Jafar, Nawab Siraj-ud-Daulah's commander in chief as well as much of the Bengal Subah's armies being earlier committed against an Afghan invasion led by Ahmad Shah Durrani against the Mughal Empire.

The battle was waged during the Seven Years' War (1756–1763), and, in a mirror of their European rivalry, the French East India Company (La Compagnie des Indes Orientales)[1] sent a small contingent to fight against the British.

Mir Jafar, Rai Durlabh and Yar Lutuf Khan thus assembled their troops near the battlefield but made no move to actually join the battle.

The British now had a great deal of wealth and influence over the Nawab, Mir Jafar, and as a result, they were able to get important concessions for earlier losses and trade income.

[8][9] The War of the Austrian Succession (1740–1748) marked the beginning of the power struggle between Britain and France and of European military ascendancy and political intervention in the Indian subcontinent.

The Nawab of the Carnatic Anwaruddin Khan intervened in support of the British and the combined forces advanced to retake Madras, but despite vast superiority in numbers, the army was easily crushed by the French.

As retaliation to the loss of Madras, the British, under Major Lawrence and Admiral Boscawen, laid siege to Pondicherry but were forced to raise it after thirty-one days.

The Treaty of Aix-la-Chapelle in 1748 forced Dupleix to yield Madras back to the British in return for Louisbourg and Cape Breton Island in North America.

[8][11] On 1 September 1751, 280 Europeans and 300 sepoys under the command of Captain Robert Clive attacked and seized Arcot, the capital of the Carnatic, finding that the garrison had fled the night before.

Raza Sahib, learning of the imminent Maratha approach, sent a letter to Clive asking him to surrender in return for a large sum of money but this offer was refused.

In the morning of 24 November, Raza Sahib tried to mount a final assault on the fort but was foiled in his attempt when his armoured elephants stampeded due to the British musketry.

With success at Arcot, Conjeeveram and Trichinopoly, the British secured the Carnatic and Wallajah succeeded to the throne of the Nawab in accordance with a treaty with the new French governor Godeheu.

[citation needed] He was well-informed of the situation in southern India, where the British and the French had started a proxy war using the local princes and rulers.

[17][18][19][20][21] The prisoners who were captured at the siege of Calcutta were transferred by Siraj to the care of the officers of his guard, who confined them to the common dungeon of Fort William known as The Black Hole.

[23][24][25][26] When news of the fall of Calcutta broke in Madras on 16 August 1756, the Council immediately sent out an expeditionary force under Colonel Clive and Admiral Watson.

A letter from the Council of Fort St. George, states that "the object of the expedition was not merely to re-establish the British settlements in Bengal, but also to obtain ample recognition of the Company's privileges and reparation for its losses" without the risk of war.

[29][26][30] On 9 January 1757, a force of 650 men under Captain Coote and Major Kilpatrick stormed and sacked the town of Hooghly, 23 miles (37 km) north of Calcutta.

A small body of their army attacked the northern suburbs of the town but were beaten back by a detachment under Lieutenant Lebeaume placed there, returning with fifty prisoners.

The fort was well-defended, but when Admiral Watson's squadron forced the blockade in the channel on 23 March, a fierce cannonade ensued with aid from two batteries on the shore.

The Nawab also moved a large division of his army under Rai Durlabh to Plassey, on the island of Cossimbazar 30 miles (48 km) south of Murshidabad.

[54][55][56][57] Mir Jafar and the Seths desired that the confederacy between the British and himself be kept secret from Omichund, but when he found out about it, he threatened to betray the conspiracy if his share was not increased to three million rupees (£300,000, which would be over £3m in 2019).

[59][60][61][62] Clive testified and defended himself thus before the House of Commons of Parliament on 10 May 1773, during the Parliamentary inquiry into his conduct in India: Omichund, his confidential servant, as he thought, told his master of an agreement made between the English and Monsieur Duprée [may be a mistranscription of Dupleix] to attack him, and received for that advice a sum of not less than four lacks of rupees.

When all things were prepared, and the evening of the event was appointed, Omichund informed Mr. Watts, who was at the court of the nabob, that he insisted upon thirty lacks of rupees, and five per cent.

The event took place, and success attended it; and the House, I am fully persuaded, will agree with me, that, when the very existence of the Company was at stake, and the lives of these people so precariously situated, and so certain of being destroyed, it was a matter of true policy and of justice to deceive so great a villain.

On 17 June, Clive despatched a force of 200 Europeans, 500 sepoys, one field piece and a small howitzer under Major Coote of the 39th Foot to capture the fort.

Following Mir Jafar's exit from the Nawab's tent, Rai Durlabh urged Siraj to withdraw his army behind the entrenchment and advised him to return to Murshidabad leaving the battle to his generals.

When Clive received the message, he hurried to the detachment and reprimanded Kilpatrick for his actions without orders and commanded to bring up the rest of the army from the grove.

Clive, unaware that it was Mir Jafar's division, supposed that his baggage and stores were the intended target and sent three platoons under Captain Grant and Lieutenant Rumbold and a field piece under John Johnstone, a volunteer, to check their advance.

However, since the wealth of Siraj-ud-daulah proved to be far less than expected, a council held with the Seths and Rai Durlabh on 29 June decided that one half of the amount was to be paid immediately – two-thirds in coin and one third in jewels and other valuables.

[122][123] The struggle continued in areas of the Deccan and Hyderabad such as Arcot, Wandewash, Tanjore and Cuddalore, culminating in 1761 when Col. Eyre Coote defeated a French garrison under de Lally, supported by Hyder Ali at Pondicherry.