 Complete the following phrase:  Pompey initially assured Rome and the senate that he could defeat Caesar in battle should he march on Rome. However, by the spring of 49 BC, when Caesar crossed the Rubicon river with his invading forces and swept down the Italian peninsula towards Rome, Pompey ordered the abandonment of Rome. Caesars army was still under-strength, with certain units remaining in Gaul, but on the other hand Pompey himself only had a small force at his command, and that with uncertain loyalty having served under Caesar. Tom Holland attributes Pompeys willingness to abandon Rome to waves of panicking refugees as an attempt to stir ancestral fears of invasions from the north. Pompeys forces retreated south towards Brundisium, and then fled to Greece. Caesar first directed his attention to the Pompeian stronghold of Iberia but following campaigning by Caesar in the Siege of Massilia and 