When the Nawab of the Carnatic, Muhammed Ali Khan Wallajah was dethroned by Chanda Sahib in 1751, he fled to Tiruchirappalli and set up his base there. The subsequent siege of Tiruchirappalli by Chanda Sahib led to the Second Carnatic War between the British East India Company and Muhammed Ali Khan Wallajah on one side and Chanda Sahib and the French East India Company on the other. The British were successful in the war and Wallajah was restored to the throne. Tiruchirappalli was invaded by Nanjaraja and Hyder Ali of Mysore kingdom in 1753 and 1780, respectively, but both of these attacks were repulsed by the troops of the British East India Company. A third attempt, by Tipu Sultan, son of Hyder Ali in 1793, ended in a stalemate.
The Carnatic kingdom was annexed by the British in July 1801 as a consequence of the alleged discovery of secret correspondence, during the Anglo-Mysore Wars, between the Tipu Sultan, an enemy of the Madras government, and Umdat Ul-Umra, the Nawab at the time. Tiruchirappalli was incorporated into the Madras Presidency, the same year, and the district of Trichinopoly was carved, with the city of Trichinopoly or Tiruchirappalli as its capital.
During the Company Raj and later, the British Raj, Tiruchirappalli emerged as one of the most important cities in India. It was popular throughout the British Empire for its unique variety of cheroot known as the Trichinopoly cigar. According to the 1871 Indian census, the first in British India, Tiruchirappalli had a population of 76,530 making it the second largest city in Madras Presidency, next only to the capital city of Madras.
In the early 20th century, Tiruchirappalli grew further, achieving a decadal population growth rate of 36.9 per cent during the period 1941–51. However, following India's independence in 1947, Tiruchirappalli has fallen behind other cities as Salem and Coimbatore in terms of growth. As of 2001, Tiruchirappalli was the fourth largest city in Tamil
