In addition, Hamilton had four illegitimate children. These were Lt. Col. Sir James Abercrombie, 1st Baronet, born prior to 1680, who died at Dunkirk in 1724. Sir James entered the Royal Scots, rose to the rank of Lieutenant Colonel and fought in the Battle of Blenheim as Aide-de-Camp to his uncle George Douglas-Hamilton, 1st Earl of Orkney. He went on to become a Whig MP for Dysart Burghs in 1710. Hamilton had a further illegitimate son, Sir Charles Hamilton KCB, born to Lady Barbara FitzRoy, he married first Elizabeth, daughter of the Hon. John Campbell of Mamore and had a son christened William James (the surname was taken after his grandfather), but he died in infancy. The main reason for the name change was to distance him from the Hamilton family who had sent Charles out to France after the disgrace of his father's affair and bastard child. While in France Charles Hamilton was styled Count of Arran. Elizabeth later died and Charles remarried Antoinette Courtney, daughter of Charles Courtney of Archambaud and had a son by her, Charles Stuart FitzRoy Douglas-Hamilton James (christened with the surname James as with his older brother) who returned to England and began a military career, finally settling in Dorset. Charles on returning to England went into the Army, became a Lieutenant Colonel in the Royal Scots Greys and was created a Knight Companion of the Order of the Bath. He went on to marry Catherine, daughter of Sir Gerrard Napier, 5th Baronet of Middle March and had a son, who married firstly the granddaughter of the 3rd Earl of Aboyne and secondly the daughter of John Montagu, 5th Earl of Sandwich he had issue by both. Hamilton also had two daughters named Ruthven.