In 50 BC, the Senate, led by Pompey, ordered Caesar to return to Rome and disband his army because his term as Proconsul had finished. Moreover, the Senate forbade Caesar to stand for a second consulship in absentia. Caesar thought he would be prosecuted and politically eliminated if he entered Rome without the immunity enjoyed by a Consul or without the power of his legions. So he refused to act as ordered and crossed the Rubicon river (the frontier with Italy ) on January 10, 49 BC and civil war broke out. According to several historians Caesar said " Alea Jacta Est " (the die is cast) upon crossing the Rubicon. This was the beginning of a succession of well succeed military campaigns of one of the finest orators and authors of prose in Rome in his times. This quotation represented the motivation of Julius Caesar that arose from the critical decision of not return to Rome as he was ordered, and triggered an inexorable cascade of events capable of changing its era. The allegory is the "Alea Jacta EST" challenge.