(i) Lord Wellesley conquered the unconquered regional kingdoms of South India- Mysore and Maratha empire.

(ii) In 1799, Tipu Sultan of Mysore was defeated and killed by the English East India Company forces. With this defeat the English established their control over Mysore.

(iii) The three Anglo-Maratha wars during 1772-1818 weakened the Maratha empire. Through these wars the British also secured the Maratha territories.

(iv) Thus, under the command of Wellesley, the British had secured the entire region of southern India (with the exception of small enclaves of French and local rulers). 

 Subsidiary Alliance System-Merits and demerits:

(i) The Subsidiary Alliance System was also introduced by Lord Wellesley in and after 1798

(ii) The British, under the Subsidiary Alliance system, agreed to protect the Indian rulers against external threats and internal disorder but, in return, the Indian rulers who accepted this system agreed to the stationing of British contingent for whose maintenance they would pay a subsidy to the British.

(iii) The ruler under the Subsidiary Alliance could neither enter into alliance with any other power nor fight a war without prior permission from the British. A British resident was stationed at these ruling states that had the authority to interfere in state politics.

(iv) This system was suited best to the advantage of the British as, without even spending a single penny the British were able to maintain large forces.

(v) This system enabled the English to weed Out the foreign influence from the Indian courts