Location: 38.936N 20.744E

Can we understand why Marcus Antonius, Antony, lost?

The most detailed description of the famous naval battle of Actium is probably provided by William Murray (2002, Age of Titans, p 232-244). He argues that the maxi-galleys (the “Titans”) are meant for besieging coastal cities more than for naval battle. Antony inherited this tactic from the prestigious Demetrius Poliorcetes who developed it three centuries earlier.

Antony’s ambition was nothing less than the conquest of Italy where Octavian (“Caesar”, future Augustus) was in power. He probably intended to attack cities like Brindisi or Taranto with his maxi-galleys (Murray, 2002, p 243). Antony thus stationed his fleet inside the Ambracian Gulf, rather on the southern banks, near Anactorium. In order to block the way to Italy, Octavian and Agrippa were positioned on the northern coast, near Nicopolis and their fleet was anchored and/or beached on the long Comarus beach (now Mitikas).

The local configuration

Antony had been around for months and he must have known the configuration of the Ambracian Gulf outlet:

Outlet of the Ambracian Gulf (Rod Heikell, 2002, p 68)
  • A bar with shallows up to -2 m to -4 m. The distance between the -5 m isobaths on each side of the bar is around 1500 m (a channel is now dredged at -7 m). It may be assumed that sea level rise of nearly 1 m over 2000 years does not interfere as a sandy or silty seabed just follows the sea water level. However, episodic changes may occur due to storms.
  • Dominant winds from NW during summer, including September, set in around noon with a force of 2 to 5 on the Beaufort scale (5 to 20 knots), and with a light land wind in the morning (1 to 5 knots), according to Rod Heikell (p 38). This corresponds to a typical breeze regime.
  • A semi-diurnal tide of 0.05 m, up to 0.25 m (Ferentinos, 2010) but possibly also some water table tilting due to wind friction inside the gulf.
  • Density currents with a salt wedge effect flowing underneath brackish water from two rivers Arachthos and Louros (resp. 63 and 2 m3/s average annual discharge) inducing an up to 1 knot surface flow velocity in the outlet (Ferentinos, 2010).
  • Both latter effects generate currents of 1 to 3 knots, in both directions, in the modern channel outlet, according to Rod Heikell (p 69).

The storm occurring during 4 days before the naval battle on September 2, 31 BC, probably blowed from NW, generating waves running southwards parallel to the coastline and producing an unacceptable rolling of ships, hampering any naval battle. In addition, these waves may have transported much sediment and displaced the shallows of the bar at the gulf outlet.

This storm probably also induced a tilting of the gulf’s water table: the large shallow water areas in the north of the gulf may have been emptied to fill the southern part near the outlet of the gulf. Hence, gulf water possibly escaped to sea. Consequently, sea water would have to refill the gulf after the end of the storm.

At dawn of September 2, 31 BC, Antony is perhaps missing a land wind to exit the gulf, he may even have an adverse refilling current occurring after the storm, and rivers may have a reduced discharge in this season not providing him with an outbound fresh water surface current. His largest ships (draught of 2 to 3 m) may experience some difficulty sailing between the shallows which may have been moving around at the outlet of the gulf during the storm. Moreover, some ships may be simply grounded on a shoal … Shame! The gods are against him.
On the other hand, a few hours later, Cleopatra, who stayed somewhat backwards with her fleet during the battle, will use the setting in of the NW wind to escape to the south, saving at least part of the Egyptian treasury (army wages) that Octavian would have loved to take over, according to Dio Cassius (Hist. 50, 34).

The battle

Depending on the various ancient sources, Octavian had between 250 and 400 battle ships and Antony, with his numerous oriental allies, had between 170 and 500 ships, out of which 60 Egyptian ships (Plutarch, Antony, 70). In addition, each had hundreds of supply ships. Octavian’s battle ships were mainly triremes (35 x 5 x 1 m) and liburnae of similar size. Antony’s ships were larger (quadriremes, up to decaremes) but Murray (2002, p 236) notes that his fleet probably included only about thirty ships larger than a quinquereme, i.e. only 5 to 10% of his fleet. According to Fourdirnoy (2019) a decareme might be twice as large as a trireme (70 x 10 x 2 m).

The modern channel is quite visible with shallows on both sides (Google Earth, 27/4/2017). Antony’s fleet and Octavian’s fleet were facing each other near the yellow line over a distance of 3 to 5 km.

Antony’s ships were initially anchored inside the Ambracian Gulf, while Octavian’s ships were outside. It may therefore be said that Octavian was besieging Antony and that the latter had to attempt an exit manoeuvre. For an escape, Antony positioned his ships outside the gulf in front of Octavian’s line of ships (see figure above) in order to cross it as soon as some wind would set in. Antony’s decision to remain static, pouring “dense showers of stones and arrows” from his higher and armoured ships on Octavian’s smaller ships ressembles an entrenched camp tactic that is rarely winning. This decision can be understood only if he had no other choice: his large ships were short of experienced oarsmen (Plutarch, Antony, 68) therefore not providing him with the required accuracy and speed needed to ram Octavian’s lighter ships. His strategy is thus that of an earthling, not that of an admiral.

It is quite clear that Antony was trying to avoid battle against Octavian and Agrippa in order to regroup somewhere on the Peloponnesian coast to prepare new plans to invade Italy. This is the reason why he burnt most of his under-manned Egyptian ships (scorched-earth policy). This is also the reason why he took sails and gear, which was not according to common practise, when going out for a naval battle. Murray (p 238) even suggests that he perhaps subtely rowed northwards in order to prepare to circumvent the Lefkada peninsula when the NW wind would set in.

But, as mentioned above, the gods were not with him on that day.


FERENTINOS, G., et al., (2010), “Fjord water circulation patterns and dysoxic/anoxic conditions in a Mediterranean semi-enclosed embayment in the Amvrakikos Gulf, Greece”, Elsevier, Estuarine, Coastal and Shelf Science 88, (p 473-481).

FOURDRINOY, Y., et al., (2019), ” The naval battle of Actium and the myth of the ship-holder: the effect of bathymetry”, 5th MASHCON International Conference on Ship Manoeuvring in Shallow and Confined Water with non-exclusive focus on manoeuvring in waves, wind and current, Flanders Hydraulics Research; Maritime Technology Division, Ghent University, May 2019, Ostend, Belgium, WWC007 (p 104 – 133), HAL-02139218.

HEIKELL, R. & L., (2002), “Ionian Sea Pilot”, IMRAY Publications, (263 p).

MURRAY, W. M. (2012), “The Age of Titans, the rise and fall of the great Hellenistic navies”, Oxford University Press, (383 p).

Ancient references

The following ancient authors provide details on the Actium battle (in chronological order):

VIRGIL (70-19 BC), AENEID: Book 8, Verse 671 and further

PROPERTIUS (47-14 BC), ELEGIES: Book 4, Elegy 6 (Apollo protector of Octavian)


PLINY THE ELDER (23-79 AD), NATURAL HISTORY: Book 32, Chap. 1 (the remora)

PLUTARCH (46-125 AD), LIVES: Antony, Chap. 67 à 76

TACITUS (55-120 AD), ANNALS: Book 4, Chap. 5

SUETONIUS (70-130 AD), THE TWELVE CESARS: Book 2, Chap 17-18

FLORUS (70-140 AD), ROMAN HISTORY: Book 4 Chap. 11

DIO CASSIUS (155-235 AD), ROMAN HISTORY: Book 50, Chap. 12 & 31-35

VEGETIUS (ca. 400 AD), DE RE MILITARI: Book 5, Chap. 3 & 7


Dio Cassius’s description of the battle

Hist. 50, 31-35, (translation by Earnest Cary, Harvard University Press, 1914-1927, found on Lacus Curtius, with italics by me):

” 31, 4. And when they set sail at the sound of the trumpet, and with their ships in dense array drew up their line a little outside the strait and advanced no further, Caesar set out as if to engage with them, if they stood their ground, or even to make them retire. But when they neither came out against him on their side nor turned to retire, but remained where they were, and not only that, but also vastly increased the density of their line by their close formation,
5. Caesar checked his course, in doubt what to do. He then ordered his sailors to let their oars rest in the water, and waited for a time; after this he suddenly, at a given signal, led forward both his wings and bent his line in the form of a crescent, hoping if possible to surround the enemy, or otherwise to break their formation in any case.
6. Antony, accordingly, fearing this flanking and encircling movement, advanced to meet it as best he could, and thus reluctantly joined battle with Caesar.

32, 1. So they engaged and began the conflict, each side indulging in a great deal of exhortation to its own men in order to call forth the skill and zeal of the fighters, and also hearing many orders shouted out to them from the men on shore.
2. The struggle was not of a similar nature on the two sides, but Caesar’s followers, having smaller and swifter ships, would dash forward and ram the enemy, being armoured on all sides to avoid receiving damage. If they sank a vessel, well and good; if not, they would back water before coming to grips,
3. and would either ram the same vessels suddenly again, or would let those go and turn their attention to others; and having done some damage to these also, so far as they could in a brief time, they would proceed against others and then against still others, in order that their assault upon any vessel might be so far as possible unexpected.
4. For since they dreaded the long-range missiles of the enemy no less than their fighting at close quarters, they wasted no time either in the approach or in the encounter, but running up suddenly so as to reach their object before the enemy’s archers could get in their work, they would inflict injuries or else cause just enough disturbance to escape being held, and then would retire out of range.
5. The enemy, on the other hand, tried to hit the approaching ships with dense showers of stones and arrows, and to cast iron grapnels upon their assailants.
6. And in case they could reach them they got the better of it, but if they missed, their own boats would be pierced and would sink, or else in their endeavour to avoid this calamity they would waste time and lay themselves more open to attack by other ships; for two or three ships would fall at one time upon the same ship, some doing all the damage they could while the others took the brunt of the injuries.
7. On the one side the pilots and the rowers endured the most hardship and fatigue, and on the other side the marines; and the one side resembled cavalry, now making a charge and now retreating, since it was in their power to attack and back off at will, and the others were like heavy-armed troops guarding against the approach of foes and trying their best to hold them.
8. Consequently each gained advantages over the other; the one party would run in upon the lines of oars projecting from the ships and shatter the blades, and the other party, fighting from the higher level, would sink them with stones and engines. On the other hand, there were also disadvantages on each side: the one party could do no damage to the enemy when it approached, and the other party, if in any case it failed to sink a vessel which it rammed, was hemmed in no longer fought an equal contest.

33, 1. The battle was indecisive for a long time and neither antagonist could get the upper hand anywhere, but the end came in the following way. Cleopatra, riding at anchor behind the combatants, could not endure the long and anxious waiting until a decision could be reached,
2. but true to her nature as a woman and an Egyptian, she was tortured by the agony of the long suspense and by the constant and fearful expectation of either possible outcome, and so she suddenly turned to flight herself and raised the signal for the others, her own subjects.
3. And thus, when they straightway raised their sails and sped out to sea, since a favouring wind had by chance arisen, Antony thought they were fleeing, not at the bidding of Cleopatra, but through fear because they felt themselves vanquished, and so he followed them.
4. When this took place the rest of the soldiers became both discouraged and confused, and wishing to make their own escape also in some way or another, they proceeded, some to raise their sails and others to throw the towers and the furnishings into the sea, in order to lighten the vessels and make good their escape.
5. While they were occupied in this way their adversaries fell upon them; they had not pursued the fugitives, because they themselves were without sails and were prepared only for a naval battle, and there were many to fight against each ship, both from afar and alongside.
6. Therefore on both sides alike the conflict took on the greatest variety and was waged with the utmost bitterness. For Caesar’s men damaged the lower parts of the ships all around, crushed the oars, snapped off the rudders, and climbing on the decks, seized hold of some of the foe and pulled them down, pushed off others, and fought with yet others, since they were now equal to them in numbers;
7. and Antony’s men pushed their assailants back with boathooks, cut them down with axes, hurled down upon them stones and heavy missiles made ready for just this purpose, drove back those who tried to climb up, and fought with those who came within reach.
8. An eye-witness of what took place might have compared it, likening small things to great, to walled towns or else islands, many in number and close together, being besieged from the sea. Thus the one party strove to scale the boats as they would the dry land or a fortress, and eagerly brought to bear all the implements that have to do with such an operation, and the others tried to repel them, devising every means that is commonly used in such a case.

34, 1. As the fight continued equal, Caesar, at a loss what he should do, sent for fire from the camp. Previously he had wished to avoid using it, in order to gain possession of the money; but now that he saw it was impossible for him to win in any other way, he had recourse to this, as the only thing that would assist him.
2. And now another kind of battle was entered upon. The assailants would approach their victims from many directions at once, shoot blazing missiles at them, hurl with their hands torches fastened to javelins and with the aid of engines would throw from a distance pots full of charcoal and pitch.
3. The defenders tried to ward these missiles off one by one, and when some of them got past them and caught the timbers and at once started a great fire, as must be the case in a ship, they used first the drinking water which they carried on board and extinguished some of the conflagrations, and when that was gone they dipped up the sea-water.
4. And if they used great quantities of it at once, they would somehow stop the fire by main force; but they were unable to do this everywhere, for the buckets they had were not numerous nor large size, and in their confusion they brought them up half full, so that, far from helping the situation at all, they only increased the flames, since salt water poured on a fire in small quantities makes it burn vigorously.
5. So when they found themselves getting the worst of it in this respect also, they heaped on the blaze their thick mantles and the corpses, and for a time these checked the fire and it seemed to abate; but later, especially when the wind raged furiously, the flames flared up more than ever, fed by this very fuel.
6. So long as only a part of the ship was on fire, men would stand by that part and leap into it, hewing away or scattering the timbers; and these detached timbers were hurled by some into the sea and by others against their opponents, in the hope that they, too, might possibly be injured by these missiles.
7. Others would go to the still sound portion of their ship and now more than ever would make use of their grappling-irons and their long spears with the purpose of binding some hostile ship to theirs and crossing over to it, if possible, or, if not, of setting it on fire likewise.

35, 1. But when none of the enemy came near enough, since they were guarding against this very thing, and when the fire spread to the encircling walls and descended into the hold, the most terrible of fates came upon them.
2. Some, and particularly the sailors, perished by the smoke before the flame so much as approached them, while others were roasted in the midst of it as though in ovens. Others were consumed in their armour when it became heated.
3. There were still others, who, before they should suffer such a death, or when they were half-burned, threw off their armour and were wounded by the shots which came from a distance, or again leaped into the sea and were drowned, or were struck by their opponents and sank, or were mangled by sea-monsters.
4. Those alone found a death that was tolerable, considering the sufferings which prevailed, who were killed by their fellows in return for the same service, or else killed themselves, before any such fate could befall them; for they not only had no tortures to endure, but when dead had the burning ships for their funeral pyres.
5. When Caesar’s forces saw the situation, they at first refrained from approaching the enemy, since some of them were still able to defend themselves; but when the fire began to destroy the ships, and the men, far from being able to do any harm to an enemy, could not even help themselves any longer, they eagerly sailed up to them in the hope that they might possibly gain possession of the money, and they endeavoured to extinguish the fire which they themselves had caused.
6. Consequently many of these men also fell victims to the flames and to their own rapacity. “