Macarthur returned to Australia in 1806, and took part with his father in the deposing of Governor William Bligh. Bligh, in his dispatch to Viscount Castlereagh of 30 April 1808, requested that "two of the rebels Charles Grimes and Edward Macarthur who have gone home in the "Dart" may be secured, in order to be tried in due time". On Macarthur's arrival in England, he entered the army as an ensign in the 60th regiment, serving at Corunna and in Sicily. In 1809, he was promoted to the rank of lieutenant. As part of the 39th Regiment he took part in the Duke of Wellington's campaigns in the Peninsular War and in France. In 1820 or 1829 he became a captain. In 1824 he paid a visit of 10 months to Australia as an agent of Thomas Potter Macqueen. After Macarthur's return to England, he was for some years secretary to the Lord Chamberlain. In 1826 he was promoted to the rank of major and in 1837 he was on the staff in Ireland.