As a young general, Pompey made a weighty mistake. It occurred at his first “triumph,” the honor awarded to certain commanders to parade captives and booty through Rome after a great victory.

In the Roman triumph, a slave would ride with the general in his chariot and repeatedly whisper into his ear, “Memento mori”: Remember, you are mortal. For our parading president, this could ...

The Roman legions The Roman Empire was created and controlled by its soldiers. At the core of the army were its legions, which were without equal in their training, discipline and fighting ability.