What to read after History of the Byzantine Empire?

Two thousand five hundred and fifty-eight years ago a little fleet of galleys toiled painfully against the current up the long strait of the Hellespont, rowed across the broad Propontis, and came to anchor in the smooth waters of the first inlet which cuts into the European shore of the Bosphorus. There a long crescent-shaped creek, which after-ages were to know as the Golden Horn, strikes inland for seven miles, forming a quiet backwater from the rapid stream which runs outside. On the headland, enclosed between this inlet and the open sea, a few hundred colonists disembarked, and hastily secured themselves from the wild tribes of the inland, by running some rough sort of a stockade across the ground from beach to beach. Thus was founded the city of Byzantium...