Charles S. Robb, the 60th man elected governor of Virginia, will be only the sixth non-native of the tradition-minded Old Dominion to hold its highest office since Revolutionary War patriot Patrick Henry was chosen in 1776.

And when he is inaugurated Saturday, he will be the second son-in-law of a president to serve as governor. The first was Thomas Mann Randolph, governor from 1819 to 1822, who was married to Thomas Jefferson's daughter. Robb is a son-in-law of the late Lyndon B. Johnson.

Robb, currently Virginia's lieutenant governor, was born in Arizona and moved to Fairfax County as a high school junior. He is the first resident of suburban Northern Virginia to be elected governor, although several men from Virginia's northern counties outside the Washington area have occupied the governor's mansion in Richmond..

The area that has produced the most governors, however, has been Albemarle County and its county seat, Charlottesville, the location of the University of Virginia. It's contributed six governors--from Thomas Jefferson (1779-81), the second governor and later the nation's third president, to John Stewart Battle (1950-54). Richmond, Norfolk, Frederick County (Winchester) and Rockbridge County (Lexington) in the upper Shenandoah Valley tie for second place, with three apiece.

A thin but fact-filled book, "Governors of Virginia, 1776-1974," by Roselyn and Edwin C. Luther III (Eastern Shore News, Accomac, Va.), chronicles a lot of trivia associated with the Virginia governorship.

Its pages confirm what most students of Virginia history already know: The state is so steeped in tradition that few outlanders have been able, as was Robb, to break into its political inner circle.

According to the book, most of Virginia's governors have been native Virginians. From Gov. Patrick Henry (of "Give me liberty or give me death!" fame), who served from 1776 to 1779 and again from 1784 to 1786, through Gov. John Buchanan Floyd, who served from 1849 to 1852, all the state's governors were Virginia natives. The pattern was broken by a New York native, Joseph Johnson, who was elected from a part of Virginia that seceded during the Civil War--or, as many Virginians still call it, the War Between the States--and became West Virginia. He served from 1852 to 1856.

Johnson, incidentally, was the last governor elected by the Virginia General Assembly and also the first elected by popular vote of the state's electorate.

One other early governor, John Floyd (1830-34), was born in a part of Virginia that is now Kentucky.

It was not until 1917 that Virginia chose another non-native--Westmoreland Davis of Loudoun County (which was not yet a Washington suburb), who was born at sea to a Virginia mother and a South Carolina father. Davis served from 1918 to 1922.

The next non-Virginia native elected governor was the patriarch of modern Virginia politics, Harry F. Byrd Sr. Byrd was born in Martinsburg, W. Va. but made Winchester, Va., his home. He served as governor from 1926 to 1930 and later went on to the U.S. Senate, where his son still serves.

The more recent non-natives include James H. Price (1938-42), also born in West Virginia, and John Stewart Battle (1950-54), born in North Carolina.

The ranks of Virginia governors include three men who went on to become presidents: Jefferson (1779-81), James Monroe (1799-1802, 1811) and John Tyler Jr. (1825-27). Two fathers of presidents also were among the state's early governors: Benjamin Harrison (1781-84), father of President William Henry Harrison, and John Tyler Sr. (1801-11).

One native of Fairfax County, Gen. Fitzhugh Lee, a nephew of Gen. Robert E. Lee, also served as governor (1886-90), but he was elected from the downstate county of Stafford. Others from northern counties were James Wood (1796-99) and Frederick W. M. Holliday (1878-82), who, like Byrd, were from Frederick County (Winchester); and William Smith (1846-49, 1864-65), from Fauquier County.