(63 b.c. - a.d. 14) first Roman emperor (27 b.c. - a.d. 14); reformer, patron of arts and literature. He carried out a gigantic work of reorganization in every field of Romanlife. He brought about the formation of the senatorial and equestrian classes on a permanent basis, each of which had its own place in the governmental system. Those of the senatorial class acted as senators, and the equestrians served as governors in the imperial provinces and held other key governmental posts. Wealth became the main criterion for membership in these two classes. —State of ManCongress Approved Gls (14.5.92)