The background to the Nicopolis Crusade can be found in the rapid spread of Ottoman Turkish conquests, particularly in the southern Balkans, during the second half of the 14th century. More specifically, it was the Ottoman threat to Hungary following the failure of a Hungarian uprising against Ottoman domination in Bulgaria that provoked action from its politically fragmented territories and the worried powers beyond. By this time, the once mighty Byzantine Empire had been reduced to little more than the city of Constantinople itself. In 1391 the Sultan Bayazid I "The Lightning" besieged the city. Pope Boniface IX preached a crusade and a French-led army of 10,000 marched east. At Nicopolis on the Danube they met the Ottoman army in battle. Ignoring the advice of their Hungarian and Transylvanian allies the Crusaders charged the Turks and were in turn smashed by the Ottoman heavy cavalry. The last Crusade ended on the banks of the Danube as the Crusaders desperately sought to escape from the pursuing Turks. David Nicolle discusses this climax to the last great French-led crusade. Researched entirely from primary sources, much of the material in the book has never been published before.