The first battle between the British and the Marathas was the First Anglo-Maratha War which began in 1774 and resulted in the 1782 treaty of Salbai . The treaty meant that the island of Salsette , next to Bombay island , was given to the British . The first conflict between the British and the Marathas was the First Anglo-Maratha War which began in 1774 and resulted in the 1782 treaty of Salbai , by which the island of Salsette , adjacent to Bombay island , was ceded to the British , while Bharuch was ceded to the Maratha ruler Scindia .