In the year 1660, a massive circular drum of stone and brick rose from the muddy banks of the Meghna River, designed not to house a king, but to crush the very idea of piracy. This structure, known today as Idrakpur Fort, was the central pivot of a deadly triangular defense strategy engineered by Mir Jumla II, the ambitious governor of Bengal under the Mughal Empire. While history often remembers the Mughals for their grand palaces and artistic patronage, their control over Bengal was constantly threatened by a chaotic sea of Portuguese and Magh pirates who used the region's complex river network to loot wealthy cities like Dhaka and Sonargaon. Mir Jumla, a former maritime trader turned military governor, understood that the rivers were the lifelines of the province and the highways of destruction for his enemies. He did not simply build a wall; he constructed a kill zone where the water itself became the executioner.
The Governor Who Ruled
Mir Muhammad Saeed Ardestani, better known as Mir Jumla II, was a man of contradictions who rose from a life of commerce to command the fate of an empire. Before he was the Subahdar of Bengal, he was a successful trader in maritime trades, a background that gave him an intimate understanding of the river currents and the tactics of the pirates who preyed upon them. His ascent to power was fueled by the chaos of the Mughal civil war, which erupted when Emperor Shah Jahan fell ill and his sons fought for the throne. Shah Shuja, the second son and the Subahdar of Bengal, attempted to march on Agra to seize the imperial crown, but Mir Jumla rushed to Bengal to stop him, forcing Shah Shuja to retreat in disgrace. Following this victory, the new Emperor Aurangzeb appointed Mir Jumla as the governor of Bengal, a region that was the stronghold of his rival. Mir Jumla immediately shifted the capital from Rajmahal to Dhaka, recognizing that the city's vulnerability to river attacks required a new kind of leadership and a new kind of fortification.The Triangular Net
The defense of Dhaka relied on a geometric precision that turned the geography of the rivers into a weapon. Idrakpur Fort was not an isolated structure but the center of a three-point strategy that included the Hajiganj Fort on the western bank of the Shitalakshya River and the Sonakanda Fort on the eastern bank. This triangular formation was designed to trap any pirate fleet attempting to navigate the junction of the Meghna, Shitalakshya, Ichhamati, and Dhaleshwari rivers. When pirates tried to advance toward the capital, Mughal soldiers would open fire with mortars from the cannons of their 200 battleships and the heavy guns of Idrakpur Fort, leaving the enemy with no option but to retreat or die in the water. If any ships managed to survive this initial barrage and push forward, the Sonakanda and Hajiganj forts would unleash round-shots to sink the remaining vessels. This coordinated fire meant that the rivers, once a highway for plunder, became a noose that tightened around any aggressor.