Strangely, Siraj had a strong hold on his grandfather, Alivardi Khan. The old man had had no sons of his own, only three daughters, and after the death from smallpox of his only other grandson, Siraj’s elder brother, all his hopes rested on the survivor. Even when Siraj had revolted against Aliverdi in 1750 and seized Patna, the fond grandfather had forgiven him. For some time there was hope that Aliverdi Khan might see sense and appoint as successor his generous and popular son-in-law, Nawazish Khan, who was married to his eldest daughter. According to the consensus of the court, this would have been the perfect choice.
But instead, in 1754, Siraj was formally named his heir. By 1755, this had become a matter of real concern, for it was clear to everyone that the eighty-year-old Nawab, stricken with dropsy, was nearing the end. At around this time, he received reports that the English had built fortifications around Calcutta against his express orders against this since they feared an attack by the French. They were defiant and insolent which did not please the Nawab.
But before he decided on his course of action, Alivardi died and was succeeded by Siraj ud-daula. He had strained relations with the English and he decided on an aggressive course of action rather than the diplomatic means preferred by Alivardi. Accordingly, he marched off with his army, 70,000-strong, to conquer Calcutta, and bring its arrogant merchants to heel. The English thought that the new Nawab was merely bluffing and would never dare to attack Fort William. But in the battle that followed, they were hopelessly outnumbered and defeated.
Six months later, troops led by Clive reached Calcutta from Madras and retook it. He then declared war on Siraj ud-Daula in the name of the Company; the first time that the EIC had ever formally declared war on an Indian prince. Two weeks later, Siraj ud-Daula again descended on Calcutta with a 60,000 strong army. In the battle that followed, the English managed to terrify Siraj into signing a treaty which restored almost all their privileges.
The situation was now complicated by the outbreak of hostilities globally between the British and the French in what became known as the Seven Year War. As part of this war, the British captured the nearby French colony of Chandernagar. Siraj was in two minds about who to support - his relations with the French were better but he dare not offend the British. At one point he sent a relief force towards Chandernagar, hesitated, and then withdrew it. A day later, he sent a message to Clive telling of his 'inexpressible pleasure’ at his victory. With the message he sent a present. But it was now too late.
There the whole Bengal campaign would have ended, but for the hatred and disgust now felt for Siraj ud-Daula by his own court, and especially Bengal’s all-powerful dynasty of bankers, the Jagat Seths. He had alienated many of his grandfather’s old military commanders, particularly the veteran general Mir Jafar Ali Khan, an Arab soldier of fortune. Mir Jafar had helped in many of Aliverdi’s most crucial victories and had led the successful attack on Calcutta. But having taken the town and defeated the Company in battle, he had then been sidelined, and the governorship given instead to a Hindu rival, Raja Manikchand. He and many others were tired of living under such an administration.
They now decided to use the EIC’s military forces to overthrow Siraj. The Company learned that Mir Jafar was prepared to offer the Company the vast sum of 2.5 crore rupees if they would help him remove the Nawab. Further investigation by the EIC revealed that the scheme had wide backing among the nobility but that Mir Jafar, an uneducated general with no talent in politics, was simply a front for the real force behind the coup – the Jagat Seth bankers. The offer was increased to Rs.2.8 crore, a further Rs110,000 a month to pay for Company troops, zamindari rights near Calcutta, a mint in the town and confirmation of duty-free trade. Dalrymple writes:
This was something quite new in Indian history: a group of Indian financiers plotting with an international trading corporation to use its own private security force to overthrow a regime they saw threatening the income they earned from trade.
Then came the Battle of Plassey after a lot of hesitation on the part of Mir Jaffer. Siraj's army was about twenty times larger than that of the Company and luck in the form of a storm was required for the latter to win. The Company troops made sure to keep their powder and fuses dry under tarpaulins; but the Mughals did not. Naturally, Siraj's guns were silenced while the Company's guns were not and it is not hard to guess who won. Thus it was that fortuitously, Mir Jaffer became Nawab of Bengal.
Now a fugitive, Siraj ud-Daula fled the capital. A fakir he had oppressed in the past recognized him and gleefully informed his enemies. He was caught and brought back to Murshidabad and brutally put to death. He was only twenty-five years old.