The Marathas invaded Tiruchirappalli in the year 1741 and imprisoned Chanda Saheb, but Chanda Saheb got himself freed and in the year 1748 involved himself in a great war for the Nawab's place in the Carnatic against Anwardeen, the Nawab of Arcot and his son Mohammed Ali. Mohammed Ali took over the two palayams of Ariyalur and Udayarpalayam, located with troops in the Ariyalur district on the grounds of default in payment of tributes and not able to assist him in crushing the rebellion of Yusuf Khan.
In the month of November 1764, Mohammed Ali represented the issue to Madras Council and got the military assistance on the 3rd of January 1765. Umdat-Ul-Umara and Donald Campbell entered Ariyalur along with the forces and captured it. The young Poligar and his followers escaped to Udayarpalayam. On 19th January the army marched upon Udayarpalayam and there the Poligar's troops were defeated and the palayams were occupied. The two poligars fled and took shelter in Tharangampadi, a Danish settlement at that time. The seizure of the palayam gave the Navab undisputed possession of all his territories extending Arcot to Tiruchirapalli.
Thus, the history of Ariyalur followed a power struggle between Hyder Ali and later Tipu Sultan with the British. After the death of Tipu Sultan, the English took over the civil and military administration of the Carnatic in their hands in the year 1801. Thus Tiruchirappalli became a part of the British-ruled India and the district was formed in 1801. The Tiruchirappalli district was trifurcated in the year 1995 and the Perambalur and Karur district were formed. Perambalur district was further divided into Perambalur and Ariyalur district in the year 2001 and merged with Perambalur in the year 2002. Then the district of Ariyalur got bifurcated from Perambalur and started to function as a new district from 23rd November 2007.