Mir Jafar in the context of "Nawab of Bengal"

The Battle of Plassey was a decisive victory of the British East India Company, under the leadership of Robert Clive, over the Nawab of Bengal and his French allies on 23 June 1757. 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 helped the British East India Company take complete control of Bengal in 1773. Over the next hundred years, they continued to expand their control over vast territories in the rest of the Indian subcontinent and Burma.

The battle took place at Palashi (Anglicised version: Plassey) on the banks of the Hooghly River, about 150 kilometres (93 mi) north of Calcutta (now Kolkata) and south of Murshidabad in West Bengal, then capital of Bengal State. The belligerents were the British East India Company, and the Nawab Siraj-ud-Daulah, the last independent Nawab of Bengal. He succeeded Alivardi Khan (his maternal grandfather). Siraj-ud-Daulah had become the Nawab of Bengal the year before, and he had ordered the English to stop the extension of their fortification. Robert Clive bribed Mir Jafar, the commander-in-chief of the Nawab's army, and also promised to make him Nawab of Bengal. Clive defeated Siraj-ud-Daulah at Plassey in 1757 and captured Calcutta.

Company rule in India (also known as the Company Raj, from Hindi rāj, lit. 'rule') refers to regions of the Indian subcontinent under the control of the British East India Company (EIC). The EIC, founded in 1600, established its first trading post in India in 1612, and gradually expanded its presence in the region over the following decades. During the Seven Years' War, the East India Company began a process of rapid expansion in India, which resulted in most of the subcontinent falling under its rule by 1857, when the Indian Rebellion of 1857 broke out. After the rebellion was suppressed, the Government of India Act 1858 resulted in the EIC's territories in India being administered by the Crown instead. The India Office managed the EIC's former territories, which became known as the British Raj.

The range of dates is taken to have commenced either in 1757 after the Battle of Plassey, when the Nawab of Bengal Siraj ud-Daulah was defeated and replaced with Mir Jafar, who had the support of the East India Company; or in 1765, when the Company was granted the diwani, or the right to collect revenue, in Bengal and Bihar; or in 1773, when the Company abolished local rule (Nizamat) in Bengal and established a capital in Calcutta, appointed its first Governor-General of Fort William, Warren Hastings, and became directly involved in governance. The East India Company significantly expanded its influence throughout the Indian subcontinent after the Anglo-Mysore Wars, Anglo-Maratha Wars, and Anglo-Sikh Wars. Lord William Bentinck became the first Governor General of India in 1834 under the Government of India Act 1833.

Robert Clive, 1st Baron Clive, KB, FRS (29 September 1725 – 22 November 1774), also known as Clive of India, was the first British Governor of the Bengal Presidency. Clive has been widely credited for laying the foundation of the British East India Company (EIC) rule in Bengal. He began as a "writer" (the term used then in India for an office clerk) for the EIC in 1744, however after being caught up in military action during the fall of Madras, Clive joined the EIC's private army. Clive rapidly rose through the military ranks of the EIC and was eventually credited with establishing Company rule in Bengal by winning the Battle of Plassey in 1757. In return for supporting the Nawab Mir Jafar as ruler of Bengal, Clive was guaranteed a jagir of £90,000 (equivalent to £10,200,000 in 2023) per year, which was the rent the EIC would otherwise pay to the Nawab for their tax-farming concession. When Clive left India in January 1767 he had a fortune of £401,102 (equivalent to £67,900,000 in 2023) which he remitted through the Dutch East India Company.

Blocking impending French mastery of India, Clive improvised a 1751 military expedition that ultimately enabled the EIC to adopt the French strategy of indirect rule via puppet government. In 1755 he was hired by the EIC to return to India, where he secured the company's trade interests by overthrowing the ruler of Bengal, the richest state in India. Back in England from 1760 to 1765, he used the wealth accumulated from India to obtain an Irish barony from the Prime Minister, Thomas Pelham-Holles, and a seat in Parliament via Henry Herbert, 1st Earl of Powis, representing the Whig party in Shrewsbury, Shropshire (1761–1774), as he had previously done in Mitchell, Cornwall (1754–1755).

Mir Syed Jafar Ali Khan Mirza Muhammad Siraj-ud-Daulah (1733 – 2 July 1757), commonly known as Siraj-ud-Daulah or Siraj ud-Daula, was the last independent Nawab of the Bengal Subah. The end of his reign marked the start of the rule of the East India Company over Bengal and later almost all of the Indian subcontinent.

Siraj succeeded his maternal grandfather, Alivardi Khan as the Nawab of Bengal in April 1756 at the age of 23. Betrayed by Mir Jafar, the commander of Nawab's army, Siraj lost the Battle of Plassey on 23 June 1757. The forces of the East India Company under Robert Clive invaded and the administration of Bengal fell into the hands of the company.

The Battle of Chinsurah, also known as the Battle of Biderra or the Battle of Hoogly, took place on 25 November 1759 near Chinsurah during the Seven Years' War. It was fought between forces of the British East India Company (EIC) and the Dutch East India Company (VOC), the latter of whom had been invited in 1759 by the Nawab of Bengal, Mir Jafar, to help him expel the EIC and establish the VOC as the leading European power in Bengal.

Despite the Kingdom of Great Britain and the Dutch Republic not formally being at war, the VOC's forces advanced up the Hooghly River. They met a force of Bengal Army troops under Francis Forde at Chinsurah on 25 November, fifty kilometres from Calcutta. Forde's troops defeated the Dutch, forcing them to withdraw. Several EIC ships had earlier engaged and defeated the ships the VOC used to deliver the troops in a separate naval battle on 24 November.

Mir Qasim (d. 8 May 1777) was the Nawab of Bengal from 1760 to 1763. He was installed as Nawab with the support of the British East India Company, replacing Mir Jafar, his father-in-law, who had himself been supported earlier by the East India Company after his role in winning the Battle of Plassey for the British. However, Mir Jafar eventually ran into disputes with the East India Company and attempted to form an alliance with the Dutch East India Company instead. The British eventually defeated the Dutch at Chinsura and overthrew Mir Jafar, replacing him with Mir Qasim. Qasim too later fell out with the British and fought against them at Buxar. His defeat has been suggested as a key reason in the British becoming the dominant power in large parts of North and East India.