	Ambler was the second son of Humphry Ambler (~1681–1745) barrister of Stubbings Park Maidenhead and Bream's Buildings Chancery Lane, and his wife Ann, daughter of Charles Bream (~1662–1713) timber merchant of Bridewell and Bream's Buildings. Charles's crippled (by a fall when aged eight) epileptic elder brother, Humphry, died of a consumption unmarried in 1752. The Ambler mansion house at Stubbings was built by Humphry Ambler on the site of a small portion of forest acquired with his stepfather Richard Bassett of White Waltham and harvested for shipbuilders.