By its sack (Constantinople), Western civilization suffered a loss greater even than the sack of Rome by the barbarians in the fifth century or the burning of the library of Alexandria by the soldiers of the Prophet in the seventh- perhaps the most catastrophic single loss in all its history....Although the Latin rule along the Bosphorus lasted less than 60 years, after which the Greek Empire was to struggle on for nearly two more centuries, that Empire never recovered its strength or any considerable part of its lost dominon. Under firm and forceful leadership.... a strong and prosperous Byzantium might have halted the Turkish advance while there was still time. Instead, it was left economically crippled, territorially truncated, and powerless to defend itself against the Ottoman tide. There are few greater ironies in history that the fact that the fate of Eastern Christendom should have been sealed- and half Europe condemned to some 500 years of Muslim rule- by men who fought under the banner of the Cross.