Alexander Nesbit was a royalist who was devoted to Charles I of England. Nesbit was appointed sheriff of Berwickshire, however when the king's policies led to military confrontation with his Scottish and English subjects, Nesbit and his sons joined the king's standard at Oxford. Nesbit's eldest son, Philip, was abroad when the civil war broke out but when he returned he was knighted and given command of a regiment. Philip Nesbit was lieutenant governor of Newark-on-Trent during the Siege of Newark that was carried out by General David Leslie, Lord Newark. When Nesbit left Newark he became an officer for James Graham, 1st Marquess of Montrose. Montrose was surprised by a strong force of Covenanter cavalry at the Battle of Philiphaugh where Philip Nesbit was captured. He was then executed at Glasgow on 28 October 1646. Two of Philip's brothers, Alexander and Robert, were also killed during the Scottish Civil War. The youngest brother, Adam, survived and he was the father of the heraldic writer, Alexander Nisbet.