ABSTRACT
The simple appeal for aid from the Byzantine Empire did not in itself create the crusade. In the years 1086-89 Robert I, the Frisian, count of Flanders (1071-93) went on pilgrimage to Jerusalem. During his passage across the Byzantine Empire he agreed to send Alexius 500 mercenaries. In 1090 he was reminded of this promise in a letter from Alexius, and the troops seem to have arrived in 1091. This was not a crusade, but it was probably the kind of arrangement Alexius had in mind when he sent his envoys to the west in 1095: military aid on a temporary basis for a limited purpose. The First Crusade was clearly much more than that. When, in 1096-97, the great armies arrived at Constantinople in response to Urban’s appeal, Alexius clearly recognised that something new had been created, and he was at enormous pains to devise means of submitting it to Byzantine control. It was obvious by that stage that Urban had done much more than send an expedition of western mercenaries, but historians have been divided in seeking to understand how the appeal made at Piacenza in February 1095 was transformed into the First Crusade.
