Readers have noticed that the fifteenth century saw a remarkable flourishing of poems written in conditions of physical captivity or on the subject of imprisonment. The largest body of this poetry is from the pen of Charles of Valois, duke of Orleans, who was captured by the English at the battle of Agincourt in 1415 and not released until 1440. The longest single poem on the subject is James I of Scotland's The Kingis Quair, purportedly written at...