The Marri were traditionally raiders and slavers, though these activities were somewhat curtailed under British rule. In 1840 the Marri had ambushed the communications lines of Sir John Keane's army fighting in the First Anglo-Afghan War; a subsequent punitive expedition against the Marri was repulsed with heavy British losses. The Marri supported the British in a war with the Bugti in 1845 but in the following decades again came into conflict with the British. British officers John Jacob and Robert Groves Sandeman did much work to keep the peace but in 1880 the Marri attacked British lines of communication during the Second Anglo-Afghan War. An expedition by British Brigadier-General Charles MacGregor, led to the submission of the Marri and the payment of fines, after which there was peace until the 1910s.