But from this very position Labienus entered into communication with the opposite party, resorted at the beginning of hostilities in 705 to the headquarters of Pompeius instead of those of Caesar, and fought through the whole civil strife with unparalleled bitterness against his old friend and master in war.

We are not sufficiently informed either as to the character of Labienus or as to the special circumstances of his changing sides; but in the main his case certainly presents nothing but a further proof of the fact, that a military chief can reckon far more surely on his captains than on his marshals.

To all appearance Labienus was one of those persons who combine with military efficiency utter incapacity as statesmen, and who in consequence, if they unhappily choose or are compelled to take part in politics, are exposed to those strange paroxysms of giddiness, of which the history of Napoleon's marshals supplies so many tragi-comic examples.
He may probably have held himself entitled to rank alongside of Caesar as the second chief of the democracy; and the rejection of this claim of his may have sent him over to the camp of his opponents.
His case rendered for the first time apparent the whole gravity of the evil, that Caesar's treatment of his officers as adjutants without independence admitted of the rise of no men fitted to undertake a separate command in his camp, while at the same time he stood urgently in need of such men amidst the diffusion--which might easily be foreseen--of the impending struggle through all the provinces of the wide empire.

But this disadvantage was far outweighed by that unity in the supreme leadership, which was the primary condition of all success, and a condition only to be preserved at such a cost.
Caesar's Army This unity of leadership acquired its full power through the efficiency of its instruments.

Here the army comes, first of all, into view.
It still numbered nine legions of infantry or at the most 50,000 men, all of whom however had faced the enemy and two-thirds had served in all the campaigns against the Celts.