Annotated gallery of the first 12 emperors of ancient Rome.
Augustus, a fascinating and controversial man, may have been the most important figure in Roman history. Through his long life (63 B.C. - A.D. 14) and deeds, the failing Republic was converted to a Principate that endured for centuries
The Annals, by P. Cornelius Tacitus, Book I
The primary source (from antiquity) we have for information on the Julio-Claudian emperors.
Stemmata of the Julio-Claudian emperors
The lines of consanguinity among the first five emperors are hard to keep straight. Even with this chart, it will take time to unravel the bloodline, marriage and adoption threads, but it's a useful reference tool.