Who introduced the Subsidiary Alliance system as a means of extending British control over Indian states?

Lord Wellesley (Governor-General 1798-1805) used the Subsidiary Alliance, under which a ruler maintained a British force and accepted a Resident; Hyderabad was the first state to sign. Dalhousie is linked with the Doctrine of Lapse, Cornwallis with the Permanent Settlement, and Hastings with the Regulating Act era consolidation, so these are common traps.