Forum Romanum
Outlines of Roman History: Civil War Between Pompey and Caesar
William Morey, in his 1901 textbook, explains in this passage the conflict between Pompey and Caesar that rages across the Roman provinces.
Ibis Communications
Eyewitness to History: Julius Caesar Crosses the Rubicon, 49 Bc
A selection from Suetonius that describes the actions Caesar took at the Rubicon River, why he did it, and the effects of this move.