sar himself arrived in Gaul and, as the commencement
of the siege of Massilia still detained him in person,
he immediately despatched the greater part of his troops assembled
on the Rhone--six legions and the cavalry--along the great road
leading by way of Narbo (Narbonne) to Rhode (Rosas) with the view
of anticipating the enemy at the Pyrenees. The movement was successful;
when Afranius and Petreius arrived at the passes, they found them
already occupied by the Caesarians and the line of the Pyrenees lost.
They then took up a position at Ilerda (Lerida) between the Pyrenees
and the Ebro. This town lies twenty miles to the north
of the Ebro on the right bank of one of its tributaries,
the Sicoris (Segre), which was crossed by only a single solid bridge
immediately at Ilerda. To the south of Ilerda the mountains
which adjoin the left bank of the Ebro approach pretty close to the town;
to the northward there stretches on both sides of the Sicoris
a level country which is commanded by the hill on which the town
is built. For an army, which had to submit to a siege, it was
an excellent position; but the defence of Spain, after the occupation
of the line of the Pyrenees had been neglected, could only be undertaken
in earnest behind the Ebro, and, as no secure communication
was established between Ilerda and the Ebro, and no bridge
existed over the latter stream, the retreat from the temporary
to the true defensive position was not sufficiently secured.
The Caesarians established themselves above Ilerda, in the delta
which the river Sicoris forms with the Cinga (Cinca),
which unites with it below Ilerda; but the attack only began
in earnest after Caesar had arrived in the camp (23 June).
Under the walls of the town the struggle was maintained with equal
exasperation and equal valour on both sides, and with frequent
alternations of success; but the Caesarians did not attain their object--
which was, to establish themselves between the Pompeian camp
and the town and thereby to possess themselves of the stone bridge--
and they consequently remained dependent for their communication
with Gaul solely on two bridges which they had hastily constructed
over the Sicoris, and that indeed, as the river at Ilerda itself
was too considerable to be bridged over, about eighteen
or twenty miles farther up.

Caesar Cut Off

When the floods came on with the melting of the snow,
these temporary bridges were swept away; and, as they had