Chapter Vii. 190-221

Roman empire—The cause of its decline—First invasion of Goths, A.D. 217—Their habits—Defeat the Emperor Decius, A.D. 257—Rebellion of Egypt, A.D. 273—Franks and Allemanni—The Veneti on the coast of Gaul—Constantinople founded, A.D. 323—Its commercial advantages and harbour—The extent of its ancient trade—Black Sea and Sea of Azov—Oppressive taxation—The laws affecting shipping—Constans and Julian—Produce of certain lands applied to the sea service—Neglect and decline of commerce, and sufferings of the people—Siege of Rome by Alaric and the Goths, A.D. 408—Genseric—His capture of Rome—Rise of Constantinople—Customs’ duties—Silk trade—Naval expedition of Justinian against the Vandals, A.D. 533, and conquest of Carthage—Rise of the Muhammedan power, A.D. 622—Rapid conquests; of Jerusalem, A.D. 636; of Alexandria, A.D. 638; and of Africa, A.D. 647—Sieges of Constantinople, A.D. 668-675