The Mongols' emergence on the eastern borders of Latin Christendom might not have seemed to offer promising conditions for the spread of Christianity. The fragmentation of the Mongol empire into rival khanates after 1261-2 in no way curtailed the opportunities for Latin missionaries. The first missionaries, properly speaking, known to have visited the Mongol world were the Franciscans William of Rubruck and Bartholomew of Cremona, who set out in 1253 from Louis IX's crusade headquarters in Palestine for Sartaq's territory in the Pontic steppe. Although it would be anachronistic to speak of 'missionary theory' in the context of Catholic proselytism in the Mongol dominions, some writers - mainly back in Western Europe - did address theoretical matters. As far as possible, the missionaries endeavoured to make good the deficiencies of the spoken word with the grandeur of the liturgy, the beauty of the chant and of bell-ringing, and the use of pictures.