hereditary
obligation. This was really an extension of the principle that a man was
bound to perform certain services in the community in which he was
enrolled (his _origo_). Finally, the emperors exercised the right of
conscription, and attached to the various corporations which were in need
of recruits persons who were engaged in less needed occupations.

The burden of their charges led the _corporati_, like the _curiales_, to
seek refuge in some other profession. They tried to secure enrollment in
the army, among the _officiales_, or to become _coloni_ of the emperor or
senatorial landholders. But all these havens of refuge were closed by
imperial edicts, and when discovered the truant _corporatus_ was dragged
back to his association. Only those who attained the highest office within
their corporation were legally freed from their obligations.

Although the corporations probably retained their former organization and
officers, their active heads were now called _patroni_, and these directed
the public services of their colleges. In Rome and Constantinople the
colleges were under the supervision of the city prefects, in the
municipalities under that of the local magistrates and provincial
governors. The professional colleges are the only ones which survived
during the late empire. The religious and funerary associations vanished
with the spread of Christianity and the general impoverishment of the
lower classes.

*The coloni.* Among the agricultural classes the forces which had
developed in the course of the principate were still at work. In the
fourth century the attachment of the tenant farmers and peasant laborers
to the soil was extended to the whole empire. The status of the _coloni_
became hereditary, like that of the _corporati_. Their condition was half
way between that of freedmen and that of slaves, for while they were bound
to the estate upon which they resided and passed with it from one owner to
another, they were not absolutely under the power of the owner and could
not be disposed of by him apart from the land. They had also other rights
which slaves lacked, yet as time went on their condition tended to
approximate more and more closely to servitude. "Slaves of the soil," they
were called in the sixth century. As this status of serfdom was hitherto
unknown in Roman law, a great many imperial enactments had to be issued
defining the rights and duties of the _coloni_.

*The growth of private domains.*