Lord Wellesley introduced subsidiary system at the end of the 18th century and it proved to be an effective tool and eventually Britishers were able to control India and it lead to the establishment of British empire in India. The most important feature was the utilisation of native resources to strengthen Britishers establishment.
It increased the military strength of the Company in India at the expense of the protected states. The territories of the Company were free from the ravages of war thereby establishing the stability of the British power in India. The position of the British was strengthened against its Indian and non-Indian enemies. Under the system, expansion of British power became easy.