What originally caused this broad line of demarcation between the two? Many different things, no doubt. Certain conquered tribes became the _imrads_ of those who had defeated them. Or again, some tribes may have submitted for the sake of being allowed to settle peacefully down on lands belonging to Ihaggaren. Whatever may have been the reason, however, as time went on the Ihaggaren[6] became the owners of flocks and herds, whilst the _imrads_ never possessed any property of their own, but looked after that of their masters. The former had to fight and to protect their _imrads_, ownership of property giving them the right to demand tribute; the latter could originally only hold their fiefs at the will of their suzerains, but after many generations had passed away their tenure became so established a thing that rent was all which could be demanded. At the present day it sometimes happens that the _imrads_ are richer, better dressed, and even more influential than the Ihaggarens. When a whole tribe is seriously threatened, and the nobles are not sufficiently strong to defend themselves, the tenants are armed just as they used to be in olden times in Europe, and these tenants fight marvellously well. At the same time, except in such emergencies, it is the business of the Ihaggarens to defend the _imrads_. In the service of the _imrads_ are a class of negro slaves known as the Belle or Bellates, who have as a rule been attached to the same family for many generations. The attachment these slaves have for their Tuareg masters is really wonderful, and a positive proof that they are well treated by them. In the struggle which took place round about Timbuktu between the French and the various tribes who resisted the foreign occupation, Bellates were often taken prisoners, but however kind our treatment of them, in spite of promises of complete liberty on the one condition that they would remain with us, we were not able to keep a single one. They all ran away to rejoin their old masters. In warlike expeditions they form a very useful supplement to the Tuareg infantry, and they are quite as brave as are the free soldiers. One peculiar fact which speaks well for the Tuareg character is, that though these warriors own hereditary slaves they never sell or buy them. Before the French arrived at Timbuktu that town was the centre of the slave trade, whence captives were sent to Tripoli on the one hand and to Morocco on the other. The convoys with the melancholy processions of slaves were generally under the leadership of traders from Mosi, who brought the unhappy captives to the town and sold them to merchants from Morocco or Tuat.