Leybourne was born in 1744 the son of Anthony Leybourne. On 8 May 1763, General William Leybourne, married AnnPopham daughter of Edward Popham, Esq., of Littlecote Wiltshire. When his maternal uncle, Francis Popham, died childless in 1786, he legally assumed the name Laybourne-Popham and the couple had a son Edward William who became General Popham of Littlecott and later High Sheriff of Wiltshire.
Career
Brigadier-General Leybourne was appointed on 2 March 1771 Captain-General and Governor-in-Chief of his Majesty’s islands of Grenada, the Grenadines, St. Vincent and Tobago by King George III, taking over the position from Robert Melvill. As Governor of Grenada he was granted expenses from 1 Nov 1771 to 16 Apr 1775. Just ten years previously, the year Laybourne got married, the British had gained control of the Grenadines and placed them also under the charge of Grenada when raiding privateers began presenting a continuing threat and forcing the new Governor-in-Chief to protest to London that St. Vincent should have a separate governor and appointed gentleman planter Valentine Morris. Dominica planters also pushed for a separate government in this case because of its distance from Grenada retarding its economic progress This was a time when the Windward Islands were in the mist of British absenteeism in which any developing legislatures would be composed of people without any major landed investment in the islands, yet consisted of a large French Catholics community who themselves owned several major estates, and whose own loyalty to the Crown was considered questionable by its British residents. Making the job of finding proper persons to make a Council an impossible problem to solve for Governor Leybourne. Shortly after, and just four years before the French recaptured Grenada, Leybourne died on 16 April 1775 in St. Vincent, aged 31 years, and Lt. William Young, Governor of Tobago, was appointed to act as Governor. Amongst the many men who held important offices in the island of St Vincent, in the cemetery surrounding the cathedral of St. George, situated in Kingstown, there was a monument stood prominently to the memory of the late Excellency William Leybourne.
