The fighting-men, or warriors, who subdued and enslaved other tribes, or transformed into schalks the weaker members of their own tribe, frequently located some of them on lands or homesteads which they permitted them to cultivate for their own use, on condition of paying a rent, generally in kind, and performing various other acts of servitude. Such was the origin of the German _liti_, who afterward constituted the common people. The free, that is originally the _strong_, the _subduer_, was at the summit of the whole German social structure. He was free because he was absolute master over the weak, who had no power or strength in himself or family, and therefore was rightless. The genuine meaning of the word _frow_ (from which is derived _fri_, _free_, _freedom_,) is "the right to own" land, _liti_ and _schalks_. From _frow_ comes the _frowen_ "freemen," "rulers," "masters,"--the caste for which all others existed. Land and schalks constituted the wealth of _frowen_ or nobleman, and to acquire them the German tribes exerted all their warlike energies. All the remote Teutonic invasions, as well as those of the mediæval times, were made principally for the acquisition of land and slaves. The lands, conquered by the swords of the _frowen_, were worked by the _schalks_. The slave traffic existed and was highly developed among the primitive Germans. It was carried on at the time of Tacitus, and some investigators maintain that for long centuries it was the only traffic known among the barbarous Germans; and slavery in its worst form was in full blast in Germany when her tribes dashed themselves against the Western empire. The slaves constituted more than half of the whole Germanic population. Wirth, the most conscientious investigator of the primitive social condition of the Germanic race, estimates the proportion of freemen to slaves as one to twenty-four. All of them--_frowen_, _adelings_, nobles of all degrees, followers, vassals, _liti_ and _schalks_, lived the same simple, agrestic life. Rude in mind and of vigorous bodies, in comparatively small numbers they shattered in pieces the rotting Roman empire. First the incursions, then the definite invasions and conquests--Attila's forays from one end of Europe to the other--gave a vigorous impulse to slavery, both abroad and at home. Abroad, the invaders enslaved all that they reached--destroying, burning, devastating, impoverishing the population, and increasing the number of those forced to seek in chattelhood a remedy against starvation. At home, immense tracts of land were depopulated and abandoned, and old and new _frowen_, masters, seized upon them. Of course _schalks_ were in demand, and were supplied by traffic and kidnapping. The wars among the Germanic tribes, which were continued more or less vigorously, and the wars with neighboring populations, increased the number of slaves thrown upon the market.