Tom Swan and the Head of St George Part Three: Constantinople

A young Englishman, Tom Swan, is taken prisoner by the Turks in Constantinople and threatened with a life of slavery. But it's not really 'the Turks' but a single beautiful woman who seems to hold the strings, and Swan must plot his way to freedom. And riches. Or perhaps he'll just settle for getting out alive. He's not a professional soldier. He's really a thief and a little bit of a scholar looking for remnants of Ancient Greece and Rome - temples, graves, pottery, fabulous animals, unicorn horns.
But he also has a real talent for ending up in the midst of violence when he didn't mean to. Having used his wits to escape execution in part one, he begins a series of adventures that take him to the high seas, bedrooms in Constantinople and street duels in Italy, meetings with remarkable men - Cyriaco of Ancona and Sultan Mehmet II and the whole Sforza family - and from the intrigues of Rome to the Jewish Ghetto in Venice.