Yaqut al-Hamawi

Yaqut al-Hamawi was an Arabic geographer and biographer of Byzantine Greek birth who was enslaved as a boy, educated in Baghdad and later freed. Travelling widely as a merchant and copyist, he compiled the Mu'jam al-Buldan, a great alphabetical dictionary of places, and a dictionary of men of letters. His works preserve much information on towns of the Islamic world before the Mongol invasions.