The Emperor's Elephant - Tim Severin

Sigwulf, a Saxon prince exiled to the court of Carolus, King of the Franks, is summoned by the royal advisor Alcuin of York. Carolus has received magnificent gifts from the Caliph of Baghdad and is determined to send back presents that will be equally sensational. White is the royal colour of Baghdad so the most important gifts will be rare white animals from the Northlands.