Henry VI. Henry VI was only eight months old when his father, Henry V died of dysentry while in France. Edward VI was only slightly older than Henry III when he took the throne at nine years three months. Richard II took the throne at ten years six months. Edward V, the old man of the group, became king at twelve years five months, and also had the shortest reign of the group since he was one of the princes murdered in the Tower of London.
James 6th of Scotland (James 1 of England) was six weeks old when he was pronounced King of Scotland as his mother was forced to abdicate in his favour.