Sometime around 10 January 49 BCE, Julius Caesar, with just one of his legions from Gaul, crossed the Rubicon, the river that marked the northern boundary of Italy. The exact date is not known, nor even the location of this most historically significant of rivers. It was more likely a small brook than the raging torrent of popular imagination, and – despite the efforts of ancient writers to embellish them with dramatic appearances of the gods, uncanny omens and prophetic dreams – the reality of the surroundings was probably mundane.
