The result of this disastrous defeat was, in simplest terms, the loss of the Eastern Roman Empire's Anatolian heartland. John Julius Norwich says in his trilogy on the Byzantine Empire that the defeat was "its death blow, though centuries remained before the remnant fell. The themes in Anatolia were literally the heart of the empire, and within decades after Manzikert, they were gone." In his smaller book, "A Short History of Byzantium", Norwich describes the battle as "the greatest disaster suffered by the Empire in its seven and a half centuries of existence". Sir Steven Runciman, in his "History of the Crusades", noted that "The Battle of Manzikert was the most decisive disaster in Byzantine history. The Byzantines themselves had no illusions about it. Again and again their historians refer to that dreadful day.