Siraj-ud-Dullah is considered to wage first rebellion against the British in Bengal. He was able to win the Cossimbazar factory in Kolkata in West Bengal
from the British. However a treacherous Mir Jafar helped the British to defeat him in the Battle of Plassey in 1757.
Siraj came to the throne after his grandfather Alivardi Khan died. As soon as he came to power he faced troubles from both the quarters-from the British and from his jealous relatives. Meanwhile his Bakshi or Commander In Chief Mir Jafar conspired with Shawkat Jung to overthrow him. However the plan was unearthed and Mir Jafar was demoted and Mir Madan was made the new Bakshi. Siraj did not like the British interference in his governance and he chose to befriend the French. He attacked and captured the Cossimbazar factory in Calcutta occupied by the British. Soon the British retaliated and captured the French factory in Chandernagar. The British then advanced towards Calcutta and Siraj had to flee to Murshidabad. Mir Jafar by that time had garnered a considerable power in Murshidabad.
Siraj beg forgiveness from Mir and earned promise to get support with his force. The British army led by Robert Clive approached and the two army met in the fields of Plassey. The ever betraying Mir Jafar once again played the trick by agreeing into a secret treaty with the British. In the battlefield his men remained passive and Siraj was eventually defeated and killed. The British gained the ultimate authority of Bengal and Mir Jafar was made the Nawab just to sing to their tunes.