On January 10, 49 BC, Julius Ceasar crossed the Rubicon, thought to be the start of a civil war.
The Rubicon is a shallow river that runs from the Apennine Mountains east to the Adriatic Sea. Modern flood control, developed over centuries, has erased the Rubicon from the landscape, and as it ran through shallow flood plains, its course changed often prior to man-made flood control. Ruby or red was the root of the name, so the river was thought to be muddy with a reddish tint.
Ceasar was returning from military campaigns in the north, and the Rubicon ran a little north of San Marino and Pesaro. Pompey had been appointed sole consul, and Ceasar wanted to be the leader of Rome. The Senate feared Ceasar and had sent word to him to disband his army and stop campaigning. Pompey even accused Ceasar of insubordination and treason.
Ceasar defied the Senate and Pompey and marched on Rome, even though he was told that if he brought his army south of the Rubicon, Senate armies would meet him and kill him. Many Roman citizens though saw Ceasar as a hero and Mark Antony was also one of his supporters. As Ceasar approached Rome with a single legion, the Senate and Pompey cowered southward with two legions.
During subsequent years, Ceasar battled Pompey’s legions with mixed results. Pompey never pressed his victories, while Ceasar would not relent. At one point Ceasar drove Pompey to Egypt where one of Ptolemy’s lieutenants murdered Pompey. Later, Ceasar went against Ptolemy, installing Cleopatra as ruler and they had a son, Ptolemy XV Ceasar.
Ceasar returned to Rome, and by 47 BC had complete control. He cleverly reformed legions and continued to conquer foreign lands, but what he really wanted was for the Roman Senate to make him permanent dictator, a notion entirely counter to Roman tradition. Nonetheless, by 44 AD he had achieved such, the same year in which he was later to be assassinated.