I'm writing my Master's thesis on the changing relationships between Italian mercantile states and Byzantium from the 10th to 12th century, and wondered if anyone here had any good book recommendations of Genoa and Venice. I've read a number of good sources focused on one of the cities, with mention of the other, but I'm yet to find a good work that encompasses both equally.
David Abulafia, The Two Italies
His argument hinges on the pivotal role of Sicily in the expansion of Venice and Genoa (and to some extent Pisa) in the 10-12th century time frame, but the broader context he reconstructs is the competition/cooperation among Italians with some eye to wider Mediterranean trade.