Born in c. A.D. 55 and died in c. A.D. 117, Publius Cornelius Tacitus was a prominent Roman historian. He is unique in the way he openly criticized Autocrats in a way that had not been done since Cicero's murder in 43 B.C. Here is a list of Tacitus' works:

When reading Tacitus, one must consider that first and foremost he was a Republican, and thus was partial to exaggerate certain acts committed by authoritarians, whereas he would over glorify acts by Republicans. If one can keep this in mind, and especially when compared with other contemporaries, Tacitus' is the greatest historian for this time period. I definetly reccomend buying his books if you are interested in this topic, he is quite an accomplished author.

Other contemporanous historians:
Dio Cassius