Frigates, which are naval vessels intermediate between corvettes and destroyers, have had a significant role in the naval history of India. Although the Maratha Navy, the naval branch of the armed forces of the Maratha Empire, used Grabs and Gallivats to project naval power, the concept of frigates (formerly called sloops) was introduced by the British. HMIS Clive, HMIS Lawrence and HMIS Cornwallis, of the Aubrietia class, were some of the early sloops commissioned into the Royal Indian Navy (RIN) during the 1920s. These ships later served in the Second World War. Later, in the 1930s, sloops of the P, Anchusa, Hastings, Grimsby, and Black Swan classes were commissioned.