James Crofts, later Scott, 1st Duke of Monmouth, 1st Duke of Buccleuch, b. Apr. 9, 1649, d. July 15, 1685, son of Charles II and his mistress, Lucy Walter. Monmouth gained fame as military commander in the 1670s and moved into the center of political affairs in the early 1680s when it became apparent that Charles II would die without having produced a legitimate heir. His brother, the Catholic James II, ascended the throne in 1685 lacking wider support whilst Monmouth could not follow his father due to his birth. His attempt to seize power in 1685 ended in his execution. He had declared himself King on June 20 1685, his troops were, however, defeated at the Battle of Sedgemoor on July 6 – events which overshadow the further volumes of the Love-Letters. Wikipedia