text:  On two horns was Europe assaulted by the Moslems; first last and through the largest tract of time on the horn of Constantinople; there the contest raged for more than eight hundred years and by the time that the mighty bulwark fell (1453 ) Vienna and other cities upon or near the Danube had found leisure for growing up; so that if one range of Alps had slowly been surmounted another had now slowly reared and embattled itself against the westward progress of the Crescent