 His first experience of war was at Megray Hill, where his Highlanders scattered in the face of enemy cannon fire.Following the peace, Lord Lewis travelled to France, where he enlisted as an ordinary pikeman in an infantry regiment, in order to learn his soldiering from the ground up.After three years, he traveled to England, working his way north by serving on both sides in the English Civil War, first in the royalist army and then in the Scottish Covenanter forces of his uncle, the Earl of Argyll, the same army he had fought against in 1639.