Article: The Nawab of Bengal Siraj Ud Daulah, the de facto ruler of the Bengal province, opposed British attempts to use these permits. This led to the Battle of Plassey on 23 June 1757, in which the Bengal Army of the East India Company, led by Robert Clive, defeated the French-supported Nawab's forces. This was the first real political foothold with territorial implications that the British acquired in India. Clive was appointed by the company as its first 'Governor of Bengal' in 1757. This was combined with British victories over the French at Madras, Wandiwash and Pondichéry that, along with wider British successes during the Seven Years' War, reduced French influence in India. The British East India Company extended its control over the whole of Bengal. After the Battle of Buxar in 1764, the company acquired the rights of administration in Bengal from de jure Mughal Emperor Shah Alam II; this marked the beginning of its formal rule, which within the next century engulfed most of India. The East India Company monopolized the trade of Bengal. They introduced a land taxation system called the Permanent Settlement which introduced a feudal-like structure in Bengal, often with zamindars set in place.

Question: What ruler opposed the British use of permits and ended up at war?
Nawab of Bengal Siraj Ud Daulah