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Caesar on the Siege of Alesia (2)

Reconstruction of Caesar's fortifications at Alesia, Archéodrome Beaune (France): goads, lilies, gravestones. Photo Jona Lendering.
Roman siege works: in front the goads, then the lilies and grave stones (Archéodrome, Beaune)
Siege of Aesia (52 BCE): one of the most important battles during Caesar's conquest of Gaul. After he had taken the Gallic town, only mopping-up operations remained.

Brief account Caesar's own words

Caesar has described the siege in his Commentaries on the war in Gaul, book 7, chapters 63-90. The translation is by Anne and Peter Wiseman. Part one can be found here.

When I was informed of this by fugitives and prisoners, I began building siege works of the following kind. I had a trench dug 20 feet wide, with perpendicular sides so that it was as broad at the bottom as it was at the top. Then I moved all the other siege works back 600 meters from this trench. I did this to counter certain difficulties: the area to be enclosed was very wide and it would not be easy to man the whole circuit; the enemy might suddenly swoop down en masse on our fortifications at night, or they could possibly, during the daytime, hurl their weapons at our men while they were busy and occupied with the work., the online home of Ancient Warfare magazine

Map of Caesar's fortifications at Alesia. Design Jona Lendering. Caesar's fortifications at Alesia

So, at this distance of 600 meters, I had two trenches dug, of equal depth and each 5 meters wide. The inner one ran across the plain and the low ground, so I filled it with water diverted from the river. Behind these trenches, I erected a rampart and palisade 4 meters high. To this I added a breastwork with battlements, with large forked branches projecting at the point where the breastwork joined the rampart, to stop the enemy if they tried to climb up. Finally, I had turrets erected at intervals of about 27 meters along the entire circuit of our fortifications.

While these great siege works were being constructed, it was necessary to send out parties of men in search of timber and grain, and since this took them quite a distance from the camp, it meant that our forces available there were under strength. Sometimes the Gauls tried to attack our works by making violent sorties from several of the gates of the oppidum [1]. I therefore decided that I must make further additions to our fortifications, so that they could be defended by a smaller number of men.

A Gallic torque from Alesia. Neues Museum, Berlin (Germany). Photo Jona Lendering.
A Gallic torque from Alesia (Neues Museum, Berlin)

And so tree trunks or very strong branches were cut down, and the ends of these were stripped of bark and sharpened. Long trenches were dug, two meters deep, and the stakes were sunk into them with just the top parts projecting; they were fastened at the bottom so that they could not be pulled out. There were five rows in each trench, fastened together and interlaced, and anyone who got in among them impaled himself on the sharp points. The soldiers called them 'grave-stones'.

In front of these, pits were dug, arranged in diagonal rows to form quincunxes. They were one meter deep and tapered gradually towards the bottom. Smooth stakes as thick as a man's thigh, with sharpened ends and hardened in the fire, were set into these pits in such a way that they projected no more than four inches above the ground. To keep them firmly in position, earth was thrown into the bottom of the pits and trodden down to a depth of one foot, the rest of the space being covered with twigs and brush wood to conceal the trap. The pits were constructed in groups; each group had eight rows, three feet apart. The soldiers called them 'lilies' because of their resemblance to that flower. In front of these we had another device. Wood blocks a foot long were sunk completely into the ground, with iron hooks fixed in them, and scattered thickly all over the area. These the soldiers called 'goads'.

When these defense works were finished, I constructed another line of fortifications of the same kind, but different from the first in being directed against the enemy on the outside. This second line formed a circuit of 21 kilometers and followed the most level ground we could find. It was intended to prevent the garrisons in our siege works being surrounded, however large a force came against us. I ordered each man to provide himself with grain and fodder to last 30 days, to avoid the danger of having to leave their camps.

While this was happening at Alesia, the Gauls summoned a council of their chiefs. They decided against calling up every man capable of bearing arms, as Vercingetorix had proposed. They were afraid that with such a vast number massed together, they would be unable to control their own contingents or keep them separate, or maintain grain supplies for them. Instead they decided to order each tribe to provide a fixed number of men.

[Caesar describes the units; all in all, they number 240,000 infantry and 8,000 cavalry.]

The supreme command of this force was entrusted to Commius the Atrebatian, the two Aeduans Viridomarus and Eporedorix, and the Arvernian Vercassivellaunus, who was a cousin of Vercingetorix. Representatives chosen from the various tribes were attached to these supreme commanders to act as advisers on the conduct of the campaign.

They all set off for Alesia, eager and full of confidence. Every single one of them believed that the mere sight of such an enormous force would be too much for us, especially as we should be under attack from two directions at once; the besieged Gauls would make a sortie from the oppidum as soon as that vast relieving force of cavalry and infantry came into view outside it.

However, the Gauls besieged in Alesia did not know what was going on in the country of the Aedui. The day on which they had expected relief had gone by; their grain was all used up. So they summoned a council and discussed what was to happen to them. Various opinions were expressed: some advocated surrender, others that they should break out of the oppidum while they still had the strength.

[One Critognatus proposes cannibalism.]

When the various views had been put forward, it was decided that those who were too old or too young to fight, or too weak, must leave the oppidum. Critognatus' proposal must not be adopted until everything else had been tried. But when the time came, if there were no other way and reinforcements failed to arrive, they should put it into effect rather than surrender or submit to terms for peace.

>> to part three >>


The Roman name for Gallic towns on hill tops.
Brief account Caesar's own words
© Jona Lendering for
Livius.Org, 2001
Revision: 25 May 2008
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