The designation pozzolana is derived from one of the primary deposits of volcanic ash used by the Romans in Italy, at Pozzuoli. Nowadays the definition of pozzolana encompasses any volcanic material (pumice or volcanic ash), predominantly composed of fine volcanic glass, that is used as a pozzolan.
The Fourth Crusade and the crusading movement generally thus resulted, ultimately, in the victory of Islam, a result which was of course the exact opposite of its original intention. The Fourth Crusade is depicted in Poul Anderson 's novel There Will Be Time from the point of view of a 20th Century Time traveler who saves the life of a Byzantine girl during the carnage and falls in love with her.
It is a terrible irony that the Crusades, which were a direct result of the Catholic desire to rescue the Orthodox people, drove the two furtherâand perhaps irrevocablyâapart. The remainder of the 13th centuryâs Crusades did little better. The Fifth Crusade (1217-1221) managed briefly to capture Damietta in Egypt, but the Muslims eventually defeated the army and reoccupied the city. St. Louis IX of France led two Crusades in his life.