King Edward II (1307-1327). 18th great-grandfather of Queen Eliz II. House of Plantagenet. Reign: 20 yrs, 2 mos., 14 days. Successor: son, Edward III. He was appointed the 1st Prince of Wales by his father, King Edward I Longshanks. Considered incompetent, frivolous and unduly influenced by his "favourites", he was deposed by his wife Isabella & her lover Roger de Mortimer, and murdered in Berkeley Castle, Gloucestershire.