The fort was built by Tanjavur Maratha ruler Serfoji II (1777-1832 CE) in 1814–1815 to commemorate the successful advance of the British over Napoléon Bonaparte (15 August 1769 – 5 May 1821) in the Battle of Waterloo in 1815.The fort acted as a residence for the royal family and also as a light-house. A stone inscription reads a friend and ally of the British to commemorate triumphs of British Arms and downfall of Bonaparte
The fort is located in 20 km (12 mi) away from Pattukkottai and 65 km away from Thanjavur in a place called Chinnamanai (Vijayakumar Veerappan) alias Sarabendrarajanpattinam in shores of Bay of Bengal. The word Manora is believed to be derived from the word minar meaning tower. The fort is hexagonal structure and has eight storeys, raising to a height of 75 ft (23 m) tapering to its top. The tower is surrounded by a wall and a moat ant it resembles a fort. The monument looks like a pagoda, with arched windows, circular staircase and eaves separating one storey from the other.