King’s ransom. Sharon Penman. 2014.

Travelling home from the bloody battlefields of the Holy Land, the Crusader king, Richard the Lionheart, is shipwrecked in the Mediterranean after an encounter with pirates. He should be protected by a papal decree, but he is betrayed and captured, ending up in the clutches of the Holy Roman Emperor, who bears him a bitter grudge.

Richard is to spend fifteen months imprisoned, some of it in the notorious fortress at Trefils, which few men have ever left. Meanwhile, his mother, Eleanor of Aquitaine, is moving heaven and earth to raise a staggering ransom, travelling across Europe to buy the release of her favourite son.

But her determination may not be enough. At the eleventh hour, the Emperor announces that he has had a better offer from the French king, Philippe, and Richard’s own treacherous brother, John. They will pay an even larger sum to continue Richard’s captivity - or to turn him over to their tender mercies.