‘Castiglione: Lost Genius’ loses his genius in a sea of brown

Giovanni Benedetto Castiglione (1609–64) was, I must admit, unknown to me until I visited this show, the only Castiglione I was properly aware of being the one who wrote The Book of the Courtier published in 1528; clearly not the same man. The artist Castiglione was a tempestuous character, always losing his temper and getting into fights.