The English and French also began interfering in the internal affairs of South India and the supremacy of the English was later established. In 1758 AD French attacked Thanjavur, but were retaken by British in 1773 AD. Thanjavur became a protected state under the East India Company.
When the British invaded India in the 18th century, Thanjavur too had to face the consequences of the English rule. The year 1749 saw the British invade the state. The main aim behind this invasion was to reinstate the lost lineage of the Maharajas of Nayaks in the province. The East Indian Company made subsequent expeditions to the old city but the Marathas dissuaded their intervention.
Saraboji II, the adopted son of Tuljaji, was made the King of Thanjavur in the year 1798, after agreeing with all the conditions laid down by the British Government. A pact was signed between the English and the Maratha ruler by virtue of which the status of the Raja was reduced to a mere vassal.
On October 1799, Raja Serfoji II, who was a student of a Christian missionary of Schwartz, surrendered Thanjavur district to the East Indian Company. Thanjavur, by then, was completely under the colonial rule. The Raja, on the other hand, was allowed to control a very meager portion of the surrounding areas.
The Thanjavur administration was totally given over to the English under the Treaty of 1799 and the ruler of the Thanjavur was allowed to retain the fort of Thanjavur only with limited power of administration. After the death of Raja Serfoji in 1833, his son Shivaji took over the management of the nearby tracts until his demise in the year 1855. The late Raja Shivaji passed away without naming an heir to his property, which in turn fell into the hands of the British.
Five years after its annexation, the British replaced Nagapatinam with Thanjavur as the seat of the district administration. Under the British, Thanjavur emerged as an important regional centre. The 1871 India census recorded a population of 52,171, making Tanjore the third largest town in the Madras Presidency. After India’s independence, Thanjavur continued as the district headquarters.
The Thanjavur district was a part of the British India until 1947 after which it became an important city in Tamil Nadu.