Robert Dinwiddie (1693-1770), colonial lieutenant governor of Virginia (1751-58), born near Glasgow, Scotland. In 1754 he dispatched a force under the command of Colonel George Washington to the Ohio River valley to prevent the French from taking possession of that region. The subsequent French attack on Washington's detachment at Fort Necessity, on the present site of Pittsburgh, Pennsylvania, marked the beginning of the French and Indian War. Dinwiddie played an active part in the early campaigns of the war. In 1758 he resigned because of ill health and returned to England.