Finished book three of the Emperor series: The Field of Swords.
Part II of this book is particularly fun for the ancient history buffs out there. Caesar has joined Pompey and Crassus in the triumvirate. As part of the compromise Caesar takes his legions into Gaul. The ten-year campaign culminates with the showdown with the rebellious Vercenigetorix at the battle of Alesia. (I wish the author had provided more detail of the rebellion and the last battle, as it is fascinating and still studied in military academies to this day.)
As a victorious Caesar crosses the Alps heading back south, he learns that Crassus has been killed fighting the Parthians. The triumvirate is over, and he cannot trust Pompey. In fact, an order for Caesar to return alone to Rome means only one thing: execution. Pompey cannot tolerate a potential challenger. This book ends with Caesar taking his legions across the Rubicon. The die is cast.
The Roman civil war, the Egyptian expedition and the assassination are covered in the last book of the Emperor series: The Gods of War.