Explanations:The Subsidiary Alliance was a key policy implemented by the British East India Company to extend its control over Indian states. This system was introduced by Lord Wellesley, the Governor-General of India from 1798 to 1805. Under the terms of the Subsidiary Alliance, a state would agree to have a British resident and a British-controlled army within its territory. In return, the British would provide military protection and refrain from interfering in the internal affairs of the state. However, the British would often use the presence of their army to influence the state's policies and eventually take over the administration.
Hyderabad was the first state to enter into a subsidiary alliance with the British East India Company in 1798. The Nizam of Hyderabad, Asif Jah II, agreed to this alliance to secure British support against the threat of the Maratha Confederacy. The alliance with Hyderabad was a strategic move by the British to establish a foothold in the Deccan region and to counter the growing power of the Marathas.
Following Hyderabad, other states such as Mysore, Awadh, and the Maratha states also entered into subsidiary alliances with the British. The alliance with Mysore came after the defeat of Tipu Sultan in the Fourth Anglo-Mysore War in 1799. The alliance with Awadh was established in 1801 after the Treaty of Lucknow, and the Maratha states entered into alliances after the Third Anglo-Maratha War in 1818.
The Subsidiary Alliance system was a significant factor in the expansion of British power in India. It allowed the British to control the military and foreign policies of the states, and eventually, many of these states were annexed by the British. The system was a key part of the British strategy to consolidate their control over India and to prevent the rise of any strong native power that could challenge their authority.