Aikman was the son of an Angus laird. As a young man he inherited his family estate at Cairnie, Arbroath, enabling him to pursue art as a vocation. He emerged as the leading Scottish painter of his generation, establishing himself after the death of Sir John Baptist de Medina as the foremost painter of Scotland's elite. With the Duke of Argyll's backing, Aikman moved to London in 1720 to establish himself with similar success to that he had experienced in Edinburgh. By 1725, he was commissioned to paint a portrait of the Prime Minister, Sir Robert Walpole, and went on to paint other leading members of parliament and the aristocracy. Throughout his career he retained strong links with the Scottish community in London.