Antony moved his army rapidly, wishing to anticipate the enemy in occupying Amphipolis as an advantageous position for the battle. When he found it already fortified by Norbanus he was delighted. Leaving his apparatus there and one legion, under the command of Pinarius, he advanced with the greatest boldness and encamped in the plain at a distance of only eight stades from the enemy, and straightway the superiority of the enemy's situation and the inferiority of his own became evident. The former were on elevated ground, the latter on the plain; the former procured fuel from the mountains, the latter from the marshes; the former obtained water from a river, the latter from wells freshly dug; the former drew their supplies from Thasos, requiring carriage of only a few stades, while the latter was 350 stadesThis should be 250 stades, according to Schweighäuser, that being approximately the distance between Amphipolis and Philippi. from Amphipolis. Still it seems that Antony was compelled to do as he did, for there was no other hill, and the rest of the plain, lying in a sort of hollow, was liable to inundation at times from the river; for which reason also the fountains of water were found fresh and abundant in the wells that were dug there. Antony's audacity, although he was driven to it by necessity, confounded the enemy when they saw him pitch his camp so near them and in such a contemptuous manner as soon as he arrived. He raised numerous towers and fortified himself on all sides with ditch, wall, and palisade. The enemy also completed their fortification wherever the work was defective. Cassius, observing that Antony's advance was reckless, extended his fortification at the only place where it was still wanting, from the camp to the marsh, a space which had been overlooked on account of its narrowness, so that there was now nothing unfortified except the cliffs on Brutus's flank and the marsh on that of Cassius and the sea lying against the marsh. In the centre everything was intercepted by ditch, palisade, wall, and gates.

In this way both sides had fortified themselves, in the meantime making trial of each other by cavalry skirmishes only. When they had done all that they intended and Octavius had arrived (for, although he was not yet strong enough for a battle, he could be carried along the ranks reclining in a litter), he and Antony prepared for battle forthwith. Brutus and Cassius also drew out their forces on their higher ground, but did not come down. They decided not to give battle, hoping to wear out the enemy by want of supplies. There were nineteen legions of infantry on each side, but those of Brutus and Cassius lacked something of being full, while those of Octavius and Antony were complete. Of cavalry the latter had 13,000 and the former 20,000, including Thracians on both sides. Thus in the multitude of men, in the spirit and bravery of the commanders, and in arms and munitions, was beheld a most magnificent display on both sides; yet they did nothing for several days. Brutus and Cassius did not wish to engage, but rather to continue wasting the enemy by lack of provisions, since they themselves had abundance from Asia, all transported by the sea from close at hand, while the enemy had nothing in abundance and nothing from their own territory. They could obtain nothing through merchants from Egypt, since that country was exhausted by famine, nor from Spain or Africa by reason of Pompeius, nor from Italy by reason of Murcus and Domitius. Macedonia and Thessaly, which were the only countries then supplying them, would not suffice much longer.

Mindful chiefly of these facts Brutus and Cassius protracted the war. Antony, fearful of the same, resolved to force them to an engagement. He formed a plan of effecting a passage through the marsh secretly, if possible, in order to get in the enemy's rear without their knowledge, and cut off their avenue of supply from Thasos. So he arrayed his forces for battle with all the standards set each day, so that it might seem that his entire army was drawn up, while a part of his force was really working night and day cutting a narrow passage in the marsh, cutting down reeds, throwing up a causeway and flanking it with stone so that the earth should not fall away, and bridging the deeper parts with piles, all in the profoundest silence. The reeds, which were still growing around his passage-way, prevented the enemy from seeing his work. After working ten days in this manner he sent a column of troops by night suddenly, who occupied all the strong positions inside and built several redoubts at the same time. Cassius was amazed at the ingenuity as well as the secrecy of this work, and he formed the counter design of cutting Antony off from his redoubts. He carried a transverse wall across the whole marsh from his camp to the sea, cutting and bridging in the same manner as Antony had done, and laying a solid foundation for his rampart, thus intercepting the passage sage made by Antony, so that those inside could not escape to him, nor he render assistance to them.

When Antony saw this about noon, instantly, with rage and fury, he turned his own army, which was facing in another direction, and led it against the fortification of Cassius which lay between his camp and the marsh. He carried tools and ladders intending to take it by storm and force his way into Cassius' camp. While he was making this audacious charge, obliquely and up hill, across the space that separated the two armies, the soldiers of Brutus were provoked at the insolence of the enemy in dashing boldly athwart their front while they stood there armed. So they charged of their own volition, without any order from their officers, took them in flank, and killed as many as they could reach. The battle once begun they charged upon the army of Octavius, also, which was drawn up opposite, put it to flight, pursued it to the camp which Antony and Octavius had in common, and captured it. Octavius himself was not there, having been warned in a dream to beware of that day, as he has himself written in his Memoirs.w(s au)to\s e)n toi=s u(pomnh/masin e)/grayen. Plutarch used the same words with a single variation, substituting i(storei= (relates) for e)/grayen (has written). This identity of language would indicate that they drew from the same source, yet their accounts of the beginning of the battle differ from each other. Plutarch says that at a council of war held by Brutus and Cassius it was resolved to give battle on the following day, although Cassius favored delay; that after the resolution was taken Cassius was in good spirits, and expressed his confidence in victory; and that on the following morning the scarlet robe, which was the Roman signal of battle, was hung out in the camps of both Brutus and Cassius. Still, the two accounts are not necessarily conflicting, since one tells what took place in the republican camp, and the other what occurred in that of the triumvirs. Plutarch's authority is Messala Corvinus, who commanded a legion under Brutus, and who was probably present at the council of war, since he relates a conversation that he had with Cassius immediately after it. ( 39, 40.)

When Antony saw that battle was joined he was delighted because he had forced it, for he had been in trouble about his supplies. He judged it inadvisable to turn again toward the plain, lest in making the evolution his ranks should be thrown into disorder. So he continued his charge, as he had begun it, on the run, and advanced under a shower of missiles, and forced his way till he struck a body of Cassius' troops, which had not moved from its assigned position and which was amazed at this unexpected audacity. He courageously broke this advance guard and dashed against the fortification that ran between the marsh and the camp, demolished the palisade, filled up the ditch, undermined the works, and killed the men at the gates, disregarding the missiles hurled from the wall, until he had forced an entrance through the gates, and others had made breaches in the fortification, and still others had climbed up on the debris. All this was done so swiftly that those who had just now captured the fortification met Cassius' men, who had been at work in the marsh, coming to the assistance of their friends, and, with a powerful charge, put them to flight, drove them into the marsh, and then at once wheeled against the camp of Cassius itself. These were only the men who had scaled the fortification with Antony, the remainder being engaged in conflict with the enemy on the other side of the wall.

As the camp was in a strong position it was guarded by only a few men, for which reason Antony easily overcame them. Cassius' soldiers outside the camp were already worsted, and when they saw that the camp was taken they scattered in disorderly flight. The victory was complete and alike on either side, Brutus defeating the enemy's left wing and taking their camp, while Antony overcame Cassius and ravaged his camp with irresistible courage. There was great slaughter on both sides, but by reason of the extent of the plain and the clouds of dust they were ignorant of each other's fate. When they learned the facts they recalled their scattered forces. Those who returned resembled porters rather than soldiers, and did not at once perceive each other nor see anything clearly. Otherwise either party would have flung down their burdens and fiercely attacked the others carrying off plunder in this disorderly fashion. According to conjecture the number of killed on the side of Cassius, including slave shield-bearers, was about 8000 and on the side of Octavius double that number.Messala is the authority for this estimate of the losses. Plutarch says: "The losses of Brutus and Cassius were 8000, including the military servants, whom Brutus called Brigas. Messala says that he thinks those of the enemy were more than twice as great," evidently a a very wild guess, like most of our statistics of the casualties of battles in ancient times. ( 45.)