Antony's early service for Caesar in Gaul is unrecorded, but it was probably impressive because Caesar sent him back to Rome in 53 B.C. to run for quaestor—an election that he won. He then returned to Gaul as one of Caesar's generals and, like Decimus, left with a record full of promise.

Also like Decimus, Antony held elective office in Rome in 50 B.C. As one of the ten People's Tribunes, elected each year to represent ordinary people's interests, Antony played a role in that year's fateful clash between Caesar and his opponents in the Senate. Led by Cato, the Senate stripped Caesar of his governorship of Gaul and denied him the chance to run for a second consulship. Caesar feared that, if he returned to Rome, he would be put on trial and unfairly convicted by his enemies. Antony tried to stop the Senate from its moves against Caesar, but he was rebuffed and fled Rome for Caesar's camp.

Antony emerged in the Civil War with Pompey as Caesar's best general and an indispensable political operative. He received such key assignments as organizing the defense of Italy, bringing Caesar's legions across an enemy-infested Adriatic Sea, and linking up with Caesar in Roman Macedonia. Antony played his most important role at the Battle of Pharsalus in central Greece on August 9, 48 B.C., when he commanded Caesar's left flank in the decisive battle against Pompey. When Caesar's veterans broke Pompey's ranks, Antony's cavalry chased the fleeing enemy.

It was a sudden and terrible defeat for Caesar's enemies. They still had cards to play—hundreds of warships, thousands of soldiers, major allies, and plenty of money. But with the sight of thousands of Pompey's dead soldiers at the end of the Battle of Pharsalus, you could almost hear the sound of the political tide turning in the Sewer of Romulus.

While he spent the next year in the East, winning allies, raising money, conquering rebels, and wooing a new mistress, Caesar sent Antony back to Rome. There Antony arranged for Caesar to be dictator for the year and for himself to be Master of the Horse (Magister Equitum), as a dictator's second-in-command was called. This was Caesar's second dictatorship. It dismayed lovers of liberty. Meanwhile, traditionalists took offense at Antony's rowdy and degenerate lifestyle, which he resumed with abandon. The sources speak of wild nights, public hangovers, vomiting in the Forum, and chariots pulled by lions. It was hard to miss his affair with an actress and ex-slave with the stage name of Cytheris, "Venus's Girl," since she and Antony traveled together in public in a litter.

Both civil and military politics in Rome slipped out of Antony's hands. When proponents of debt relief and rent control turned violent, Antony sent troops into the Forum and blood flowed—the troops killed eight hundred men. Meanwhile, some of Caesar's veteran legions, now back in Italy, mutinied for pay and demobilization.

The situation called for Caesar's firm hand, and he returned to Rome in the fall. He put down the mutiny and agreed to reduce rents, although he refused to cancel debts. As for Antony, Caesar always knew how to turn people's weaknesses to his advantage. After speaking against Antony in the Senate, Caesar turned around and gave him a new assignment.

It was a job that most Romans would have turned down, but not Antony. He lacked political finesse, but he didn't mind getting his hands dirty and he was loyal. Caesar gave Antony the job of selling all of Pompey's confiscated assets to various private bidders. Pompey was the second-richest man in Rome, surpassed only by Caesar. Antony was a sector, literally, a "cutter," that is, someone who bought confiscated property at a public auction and sold it off piecemeal at a profit. The Romans considered that an ignoble profession, not suitable for a man of Antony's birth. It was not only a dirty business but a dangerous one because in 47 B.C. Pompey's allies and sons were still armed and at large. A soldier like Antony would surely prefer to win glory in the campaigns in Africa and Spain. Instead, he stayed in Rome through early 45 B.C. raising the money through his sales that Caesar needed to pay his troops. Antony was constantly short of funds and no doubt Caesar allowed him to skim a little off the top for himself.

Excerpted from The Death of Caesar by Barry Strauss. Copyright © 2015 by Barry Strauss. Excerpted by permission of Simon & Schuster. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.