Mirza Muhammad Siraj-ud-Daulah ascended the throne of Bengal in April 1756 at the age of 23, succeeding his maternal grandfather, Alivardi Khan. His brief reign of fifteen months was characterized by severe internal fractures and external colonial encroachment. Upon his accession, Siraj-ud-Daulah faced immediate succession challenges from three major internal factions:
- Ghaseti Begum: The eldest sister of Siraj’s mother, who possessed immense wealth and backed rival claimants from her base at Motijhil in Murshidabad.
- Shaukat Jung: The cousin of Siraj-ud-Daulah and the Governor of Purnea, who openly rebelled against his authority. Siraj-ud-Daulah decisively defeated and killed him at the Battle of Manihari in October 1756.
- The Court Faction: A powerful clique within the Murshidabad Durbar that opposed the young Nawab’s volatile temperament. This group included Mir Jafar (Mir Bakshi or army commander), Rai Durlabh, Jagat Seth (the state banker, Mehtab Rai), and Omi Chand (a wealthy merchant).
Structural Strains on Bengal’s Autonomy
Bengal operated as an independent subah (province) of the declining Mughal Empire, sending nominal tribute but exercising complete internal sovereignty. The financial stability of the province was structurally strained by two primary factors:
- Maratha Predatory Raids (1741–1751): The preceding decade under Alivardi Khan was dominated by the destructive invasions of the Maratha forces of Raghuji Bhonsle under commander Bhaskar Pandit. These Bargi raids forced Bengal to cede Orissa and pay an annual Chauth (one-fourth of land revenue) of 12 lakh rupees, draining the treasury before Siraj-ud-Daulah took power.
- Abuse of Imperial Dastaks: The British East India Company (EIC) systematically misused the commercial passes (dastaks) granted by Mughal Emperor Farrukhsiyar’s Farman of 1717. Designed for duty-free corporate transit, Company servants used them to exempt their private trade from internal customs duties, depriving the Nawab of vital sovereign revenue.
Direct Triggers of Conflict with the British
Sovereign Defiance and Fortification
The outbreak of the Seven Years’ War (1756–1763) in Europe prompted the British and the French to fortify their respective commercial settlements in Bengal without obtaining the Nawab’s permission. Siraj-ud-Daulah viewed this as a direct challenge to his territorial sovereignty. While the French at Chandernagore complied with his orders to cease fortification, the British at Fort William refused and continued adding military bastions.
Harboring of State Fugitives
The relationship further deteriorated when the British Governor of Calcutta, Roger Drake, granted political asylum to Krishna Das. He was the son of Rajballabh (the wealthy governor of Dacca), who had fled Murshidabad with massive amounts of misappropriated state revenue.
The Siege of Calcutta and the Alinagar Treaty
In retaliation for British defiance, Siraj-ud-Daulah marched south with his infantry, capturing the EIC factory at Kasimbazar and laying siege to Calcutta. Governor Drake and his council fled downstream to Fulta, leaving Fort William to surrender on June 20, 1756. Siraj-ud-Daulah temporarily renamed Calcutta as Alinagar and placed it under the command of Manik Chand. Following the surrender, the controversial “Black Hole” tragedy occurred. According to British survivor J.Z. Holwell, 146 British prisoners were confined overnight in a small, poorly ventilated room measuring 18 by 14 feet, resulting in the death of 123 individuals due to suffocation. Modern historians view these numbers as heavily exaggerated for wartime propaganda, but the event provided Robert Clive and Admiral Charles Watson with the justification to launch a retaliatory expedition from Madras. Clive recaptured Calcutta in January 1757, forcing the Nawab to sign the Treaty of Alinagar on February 9, 1757, which restored all British trading privileges and permitted the fortification of Calcutta.
The Battle of Plassey and the Fall of Siraj-ud-Daulah
The Murshidabad Conspiracy
Realizing that Siraj-ud-Daulah’s military strength could not be easily overcome in an open field, Robert Clive collaborated with the internal enemies of the Nawab. A secret treaty was orchestrated through the mediation of Omi Chand, which finalized the betrayal of Siraj-ud-Daulah.
| Conspirator | Official Position / Identity | Promised Reward / Role in Conspiracy |
| Mir Jafar | Mir Bakshi (Commander-in-Chief of Bengal Army) | Promised the throne of Bengal as a puppet Nawab; agreed to keep his troops stationary during battle. |
| Rai Durlabh | High-ranking Commander and Treasurer | Commanded a major division of the army; agreed to withdraw from active combat. |
| Jagat Seth | Chief State Banker (House of Seth) | Financed the conspiracy to safeguard mercantile assets from the Nawab’s seizures. |
| Omi Chand | Wealthy merchant intermediary | Acted as the diplomatic bridge; Clive deceived him using a forged treaty to deny him a promised 5% share of the treasury. |
Military Engagement at Palashi (June 23, 1757)
The Battle of Plassey was fought on the banks of the Bhagirathi River in Palashi, roughly 150 kilometers north of Calcutta. The British force consisted of 3,000 soldiers, while Siraj-ud-Daulah possessed a vast army of nearly 50,000 troops. Despite the overwhelming numerical disparity, the battle was decided before it commenced due to the pre-arranged treachery. The main body of the Nawab’s army, commanded by Mir Jafar and Rai Durlabh, remained completely inactive during the engagement. A small, loyal contingent led by Mir Madan, Mohan Lal, and a handful of French artillerymen under St. Frais fought bravely. When Mir Madan was killed by a stray artillery shell, Siraj-ud-Daulah panicked, turned to Mir Jafar for counsel, and was advised to retreat from the battlefield.
Execution and Political Aftermath
Siraj-ud-Daulah fled to Murshidabad and subsequently attempted to escape toward Patna via boat. He was captured at Rajmahal by the forces of Mir Jafar’s son, Miran. Siraj-ud-Daulah was executed on July 2, 1757, on the orders of Miran. Following his death, Mir Jafar was installed as the Nawab of Bengal, initiating the era of puppet rulers. The EIC extracted a war indemnity of over 22 million rupees and gained the absolute zamindari (revenue collection) rights over the 24 Parganas district, transforming from a commercial corporation into the primary political power-broker of India.
Key Historical Facts and Trivia for Civil Services
The Maratha Ditch
During the Bargi invasions (1742), the British obtained permission from Alivardi Khan to dig a three-mile perimeter earthwork around their settlement in Calcutta to protect it from Maratha cavalry attacks. This fortification was known as the “Maratha Ditch” and roughly corresponds to the modern-day Circular Road in Kolkata.
Structural Trait of the Treaty of Alinagar
The Treaty of Alinagar (1757) was a crucial stepping stone to British paramountcy because it legally allowed a foreign commercial entity to coin its own money within Bengal territory, a privilege that directly diluted the sovereign currency rights of the Mughal subah.
Last Modified: June 8, 2026