The History of the Decline and Fall of the Roman Empire, by Edward Gibbon

Chapter LVI: The Saracens, The Franks And The Normans

The Saracens, Franks, And Greeks, In Italy.—First Adventures And Settlement Of The Normans.—Character And Conquest Of Robert Guiscard, Duke Of Apulia—Deliverance Of Sicily By His Brother Roger.—Victories Of Robert Over The Emperors Of The East And West.—Roger, King Of Sicily, Invades Africa And Greece.—The Emperor Manuel Comnenus.— Wars Of The Greeks And Normans.—Extinction Of The Normans.