Forum Romanum
Outlines of Roman History: The Reign of Marcus Aurelius (Ad 161 180)
Read this entry from William Morey's 1901 text to find out about Marcus Aurelius, one of the five good emperors, who was known as a philosopher.
Franco Cavazzi
The Roman Empire: Marcus Licinius Crassus (D. 53 Bc)
This site explains how Crassus gained power in Rome, raised an army, became governor of Syria, and was eventually murdered.
University of Chicago
Encyclopedia Romana: Arch of Augustus
This site from the Encyclopedia Romana provides a short but informative description of the arch of Augustus which no longer stands but was erected in the Roman Forum. Gives coin evidence of the arch as well as literary evidence.