The Subsidiary Alliance System
The Subsidiary Alliance System was introduced to the Indian system by Lord Wellesley. The East India Company adopted it to be able to rule and control the Indian kingdoms in a better way. The system forced the Indian rulers to have a British army to protect the rulers and their kingdoms, and they also had to pay for the maintenance of these subsidiaries.
If any Indian rulers failed to pay for the subsidiary forces, they had to give away one of their territories as a penalty.
In a similar case, the nawab of Awadh had to surrender more than half of his territory in 1801 as he failed to pay for the British subsidiary forces.