It is easy to feel sorry for Charles I. Short and stuttering, with weak ankles, he spent his early years as an also-ran beside his glamorous and athletic elder brother, the charismatic Henry, Prince of Wales. Henry’s death in 1612 made Charles the unlikely heir to the kingdoms of England and Scotland: their mother, Anna of Denmark, couldn’t bring herself to attend his investiture as Prince of Wales four years later, and one of the officiating priests called him ‘Henry’ by mistake. After he ascended the throne in 1625, he continued to be eclipsed by more dynamic characters: his father’s former lover the Duke of Buckingham; the Earl of Strafford, whom he swore to protect and then betrayed; dashing soldiers like his nephew the ‘mad cavalier’ Prince Rupert. Perhaps the best that can be said about Charles was, as Rubens put it, he was ‘the greatest student of art among the princes of the world’. He may have been a lousy king, but at least he had good taste in pictures.