In 1734 Fairfax came to Virginia as agent for his first cousin, Thomas, Sixth Lord Fairfax (who, by direct inheritance from a royal grant of Charles II, had come into possession of some five million acres of Virginia land lying between the Rappahannock and the Potomac, and extending from Chesapeake Bay to the foothills of the Blue Ridge Mountains, known to Virginians as the Northern Neck); and to serve as Collector of Customs for the South Potomac. Fairfax first went to Westmoreland, where he was associated with the Washington and Lee families. Next he moved to King George, and lived at Falmouth. By 1741 he was representing Prince William County in the House of Burgesses. Colonel Fairfax was elevated to "His Majesty's Council of State" three years later. Becoming President of the Council in 1744, he continued in that office until his death. About this time William Fairfax completed his dwelling house, Belvoir, situated on a high bluff overlooking the Potomac River, halfway between Mount Vernon and Gunston Hall. It was described by Washington in an advertisement as having "four convenient rooms and a wide Hall on the first floor." In one of these "convenient rooms," more than two hundred years ago on July 19, 1743, Anne, eldest daughter of Colonel Fairfax was married to Lawrence Washington of Mount Vernon. A few years after his marriage, Lawrence (to whom George Washington owed his start in life) took his impecunious young half-brother into his home at Mount Vernon, whereupon the in-laws became intimately concerned with George's future. Young George was wise enough to realize that the way of advancement led through this important family and he never lost an opportunity to cultivate the President of the Council. Colonel Fairfax became a benefactor of the young man's fortunes, an inspiration to his ambition, and was truly and wholeheartedly attached through his affections to the gangling youth. To the end of his life Fairfax signed his letters to George, "Y^r very affect^e & Assur^d Friend." In 1747 George William Fairfax, the Colonel's eldest son, returned home from England, where he had received his education, with the promise from Lord Fairfax of falling heir to his father's agency of the Northern Neck.