Quote Originally Posted by andrewt View Post
They said in an interview that the Roman Empire reached its peak size-wise with Trajan even though the empire really reached its peak with Augustus. Unless I'm mistaken, I thought Hadrian added a few more territories and they only started pulling back afterwards.
The geographic peak was 117CE

http://www.worldology.com/Europe/roman_empire_imap.htm

...during the reign of Trajan:

http://en.wikipedia.org/wiki/List_of_Roman_emperors