The British Siege of Bharatpur, which took place in 1805 in the present-day Bharatpur district of Rajasthan, was a crucial episode in the Second Anglo-Maratha Wars.
The Ruler of Bharatpur, Ranjit Singh had angered the British by joining forces with the Marathas in 1804 after Yashwant Rao Holkar successfully defeated Colonel William Monson. Thus, in 1805, a massive force under the command of Lord Lake and Lt. Col. Maitland arrived at the Bharatpur fort in an effort to take control of the Kingdom. The massive walls of the fort, and the broad encircling ditch became a major problem for the colonial forces during the Siege, and despite relentless bombardment, they were not able to effect any damage to the ramparts. The defenders of the fort successfully repelled four waves of attack by the British, and inflicted heavy casualties on them, adding up to over three thousand killed. Unable to capture the fort, the British forces were compelled to retreat.
Ranjit Singh, the Raja of Bharatpur sought to establish peace with the British after the siege, and agreed to pay an indemnity and surrender his claim to the surrounding territories of Tonk, Bundi etc. However, as a result of the victory, Bharatpur remained out of British control for over twenty years, till 1825.
Source: Indian Culture Portal