If Rome, shabby and labyrinthine, stood as a monument to the rugged virtues of the Republic, then Alexandria bore witness to what a king could achieve. But not just any king. The tomb of Alexander the Great still stood talisman-like in the city he had founded, and the street plan, a gridded lattice lined with gleaming colonnades, was recognisably the same as that mapped out three centuries earlier by the conquering Macedonian, to the roar of the lonely sea.