[3] Brigadier-General Leyborne 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.

[7][8] Just ten years previously the British had gained control of the Grenadines (south of St. Vincent) 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[9] This was a time when the Windward Islands were in the midst 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 Catholic community who themselves (though having freely signed a petition of allegiance to the King) owned several major estates, and whose own loyalty to the Crown was considered questionable by its British residents.

[10][11] Shortly after, and just four years before the French recaptured Grenada, Leyborne died on 16 April 1775 in St. Vincent, aged 39 years, and Lt. William Young, Governor of Tobago, was appointed to act as Governor.

[12] 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 (which was by 1912 much affected by the rains and heat as to almost obliterate the inscription) stood prominently to the memory of the late Excellency William Leyborne.