Caesar felt himself now strong enough to give battle; but Pompeius declined it.

On the other hand Caesar succeeded in deceiving his adversary and throwing himself unawares with his better marching troops, just as at Ilerda, between the enemy's camp and the fortress of Dyrrhachium on which it rested as a basis.

The chain of the Graba Balkan, which stretching in a direction from east to west ends on the Adriatic in the narrow tongue of land at Dyrrhachium, sends off--fourteen miles to the east of Dyrrhachium--in a south-westerly direction a lateral branch which likewise turns in the form of a crescent towards the sea, and the main chain and lateral branch of the mountains enclose between themselves a small plain extending round a cliff on the seashore.
Pompeius now took up his camp, and, although Caesar's army kept the land route to Dyrrhachium closed against him, he yet with the aid of his fleet remained constantly in communication with the town and was amply and easily provided from it with everything needful; while among the Caesarians, notwithstanding strong detachments to the country lying behind, and notwithstanding all the exertions of the general to bring about an organized system of conveyance and thereby a regular supply, there was more than scarcity, and flesh, barley, nay even roots had very frequently to take the place of the wheat to which they were accustomed.
Caesar Invests the Camp of Pompeius As his phlegmatic opponent persevered in his inaction, Caesar undertook to occupy the circle of heights which enclosed the plain on the shore held by Pompeius, with the view of being able at least to arrest the movements of the superior cavalry of the enemy and to operate with more freedom against Dyrrhachium, and if possible to compel his opponent either to battle or to embarkation.

Nearly the half of Caesar's troops was detached to the interior; it seemed almost Quixotic to propose with the rest virtually to besiege an army perhaps twice as strong, concentrated in position, and resting on the sea and the fleet.

Yet Caesar's veterans by infinite exertions invested the Pompeian camp with a chain of posts sixteen miles long, and afterwards added, just as before Alesia, to this inner line a second outer one, to protect themselves against attacks from Dyrrhachium and against attempts to turn their position which could so easily be executed with the aid of the fleet.