Skene was from the branch of the family associated with Hallyards Castle. He enlisted in the British army in 1739 and saw much action: the Battle of Porto Bello (1739), the Battle of Cartagena de Indias (1741), the Battle of Fontenoy (1745), and the Battle of Culloden (1746). In 1756 he arrived in the British colonies in North America. In February 1757 he was promoted to the command of a company in the 27th (Inniskilling) Regiment of Foot. He was wounded in Lord Howe's 1758 attack on Fort Ticonderoga. In 1759 he was appointed major of a brigade and in October of that year was left in command of Crown Point with instructions to strengthen the fortifications. While he was stationed there he became convinced that the local area was a good one for trade and settlement. With the encouragement of Lord Amherst he started a small settlement at the head of Lake Champlain, purchasing land in the area.