 He joined the army and was a captain in the 33rd Foot in 1702, and captain in the Royal Horse Guards from 1711 to 1717.He served under John, the second duke of Argyll, who was distinguished both in war and in politics.Earle was commissary of musters in Spain in 1711 and commissary-general of provisions in Spain in 1711 and at Minorca from 1712 to 1717.