 The Edwardes family owned extensive lands in Pembrokeshire, Carmarthenshire and Cardiganshire and on the death of his cousin the 7th Earl in 1721 and his elder brother in 1738, William inherited the additional estates of the Rich family, which included Holland House in Kensington.In 1776 he was created Baron Kensington in the Peerage of Ireland.This was a revival of the barony held by the Earls of Warwick and Holland which had become extinct on the death of the eighth and last Earl in 1759.