The ecclesiastical _immunitas_, as early as the ninth century, was
in the eyes of all ambitious landowners the model of a privileged
estate. But it was by another road that the layman arrived at the
position of a petty sovereign. Speaking broadly, there are two stages in
his progress. First, he comes into the position of a royal tenant,
holding his lands in exchange for services and fealty. Secondly, he
acquires, by delegation or usurpation, a greater or smaller part of the
royal authority over his own dependents.

(1) The idea of a personal contract between the free warrior and his
lord, by which the former places himself at the disposition of the
latter and promises unlimited service, is one which occurs in many
primitive societies and is peculiar to no one branch of the human race.
Tacitus noticed, as one feature of German life in his time, the free
war-band (_comitatus_) who lived in the house of their chief,
followed him to battle, and thought it the last degree of infamy to
return alive from the field on which he had fallen. The Merovingian
kings maintained a bodyguard of this kind (_antrustions_). Under
the Carolingians such followers appear in the host, in the royal
household, in every branch of the administration. They are the most
trusted agents of the King and possess considerable social consequence.
They are called _vassi_, a name formerly applied to any kind of
dependent, but now reserved for free men rendering free services to the
King or some other lord, and subject to his jurisdiction. So valuableare
these followers that, in the eighth and ninth centuries, the power
of the great is largely measured by the number of _vassi_ whom they
can put into the field.

Various considerations suggested to Frankish rulers and nobles the
expediency of endowing these followers with land, and of granting land