Well google says "The first emperor, Augustus, reduced the size of the senate from 900 members to 600, even though there were only about 100 to 200 activesenators at one time."
The curia Julia in roman forum, the seat of the imperial senate. the first emperor, Augustus, reduced the size of the senate from 900 members to 600, even though there were only about 100 to 200 active senators at one time.
