How to lay Siege in the Age of Louis XIV - The
Perfect Siege of Ath 1697 (Vauban’s Masterpiece) The art of Siege Warfare was perfected in the 17th
century. Bastion forts had never been sturdier and more complex while the methods of attack became
ever more standardized and increasingly effective. To be sure, sieges remained extremely diverse, but
now there was a consistent thread running through them, culminating in an almost infallible method
created by Sébastien Le Prestre de VaubanSebastien Le Prestre de Vauban. The great French engineer of
Louis XIV demonstrated his masterful siege craft in the siege of Ath in 1697. It was considered
“[…] not so much a siege as an idealized version of one.” This is quite convenient for us, because
it saves us the trouble of re-constructing a typical 17th century siege in the way we’ve
covered medieval and 16th century siege craft. For a better overview, we are going to structure this
as an 11-Step guide. So, without further ado let’s look at the siege of Ath, a masterful example
of how to lay siege in the age of Louis XIV. In 1688 King Louis XIV of France was the most
powerful monarch in Europe. When he set out to extend his influence across the Rhine and confirm
his territorial claims, the Nine Years’ War began. France was opposed by the Grand Alliance, a
coalition of the Holy Roman Empire, the Dutch Republic, England and Spain supported by other
enemies of the Kingdom. For several years the war raged mainly in France’s borderlands (Savoy,
Rhineland, Spanish Netherlands and Catalonia) but also overseas. By 1695 almost all parties were
financially exhausted and took up negotiations for peace. While conditions were discussed at
Rijswijk, the fighting continued. According to the Historian and Vauban-expert Jamel Ostwald, this
was common in an era of fluid coalition warfare. When the Duke of Savoy, Vittorio II Amadeo,
abandoned the alliance and became neutral in late 1696, Louis seized the opportunity. He
prepared to invade the Spanish Netherlands to force the Allies to acknowledge his
territories and his pre-eminence. Amid rumors of an impending suspension of arms, France
prepared to wage war on its northern border. For his demonstration of force, Louis had a
specific place in mind: The bastion fort of Ath. Early on 16 May 1697 12’000 French cavalry arrived
before Ath. Seemingly from nowhere they surrounded the town and occupied the main roads, river
crossings, and important buildings around the town. (Step 1: Surround) This was always the first
step in a siege and often the task of cavalry. The faster a place was cut off, the less time the
defenders had to prepare. While the cavalry was patrolling the surroundings, the French siege army
advanced towards Ath. Soon, its commander, the marshal of France Nicolas Catinat and the engineer
at his side, Sebastian le Prestre de Vauban, were looking from their camp at the
formidable fortress they were facing. The fortress of Ath in modern-day Belgium had been
modernized by Vauban himself, shortly before the French had ceased it to the Spanish in the Treaty
of Nijmegen in 1678, along with several other fortresses. He had turned it into a cutting-edge
octagonal bastion fort (map2), with almost ideal proportions. The rivers Dender and Leuze meandered
around the walls and filled the ditch with water. Normally, just about 30cm, but in times of war
the water line could be raised to almost 2.5m by closing a sluice. Massive and well-placed
outworks protected the vulnerable spots and the side facing Mont Feron had been
adapted to resist fire from the heights. In short, Ath was a pretty much perfect
bastion fort according to Vauban’s standards. Now, Louis XIV called upon Vauban
to capture his own creation. While the siege army was beginning
its preparations, two other armies, in total 140’000 men, screened the surroundings
and observed the enemy. Such armies were known as armies of observation and were a reaction to
the increasingly large relief forces fielded in the 17th century. Thanks to them Catinat’s
40’000 men could completely focus on the siege. They faced a small garrison of 3’600 soldiers, 30
engineers and 30 artillerists with 32 guns. The defense was commanded by a sixty-five-year-old man
by the melodious name of Ferdinand-Gaston-Lamorald de Croy, comte de Roeux. Roeux was sluggish and
only in charge because several better-suited officers were caught by the French when they
attempted to enter the city prior to the siege. The major reason that Ath wasn’t prepared and
manned better, however, was that it had long been unclear whether the French would attack Brussels,
Oudenaarde or Ath. This had compelled the defenders to split their forces and Ath, the best
fortress but least important town came off worst. After the French cavalry had cut off the town
and camp had been made, Catinat and Vauban began to invest the town, which was the second step in
laying siege in Vauban’s way (Step 2: Investment). Assisted by 20’000 civilians, they had their men
dig a circumvallation, a complete line of defenses surrounding all siege works (map1). It consisted
of all along of eight-foot-thick breastworks, a six-foot deep ditch, wooden palisades and
v-shaped projections every 800m or so. Most of the siege army would man this line of
defense. Usually, an attacker would also build a second fortified line closer to the town,
a contravallation, to prevent surprise attacks by the defenders. At Ath, however, Vauban thought
this unnecessary because of the small garrison. At the same time bridges were constructed to
connect the camps separated by the Dender and Leuze rivers and 4,000 wagons brought 290’000
pounds of powder, about 7’000 cannonballs, 3’400 mortar bombs, 950 grenades and 12’000 sandbags to
the camp. Enormous masses of wood were collected from nearby forests, thousands of picks, shovels,
and axes readied and miles of rope furled. While the soldiers were busily preparing all
of this, small detachments of French officers snuck up to the fortress to have a closer look at
the defenses. This was the third step. (Step 3: Reconnaissance and Strategic Planning) Vauban
was among them, carefully looking for changes on the defenses he had designed thirty years
earlier and drawing up his plan for the attack. On the defenders’ side things went off tracks
right from the beginning. Roeux was barely moving a finger, so that preparations only really
began, when a young Prince, Anton Günther of Anhalt-Zerbst took over. Anhalt-Zerbst had
the men burn all buildings outside the walls to make sure the French couldn’t use them as cover,
reinforced the defenses and flooded the ditch. Then his gunners opened fire at the men working
opposite their gates. Vauban observed this, probably with a sneer on his face. He knew
all too well that his works and men were not within reach of the defenders yet. All their
salvo did, was wasting powder, making noise and revealing their exact range of fire.
On 22 May the circumvallation was almost ready. After nightfall, the trenches
were opened which was the fourth step (Map3) (Step 4: Digging Approaches). The main
direction of the attack was the Brussels gate. Silently, two battalions filed off to open two
approaches.INF An additional fake approach was made on the other side of the Dender river. While
800 soldiers excluded from guard duty took to the shovels, six regiments guarded them. Vauban
himself supervised the work as ground was broken. The men made good progress and quickly
advanced 800 meters towards the town. Just short of 600 meters from the defenses,
they began to dig the first parallel, which usually was step nr. 5 (Step 5: First Parallel).
It served as cover for the besieging army and as an assembly point – and at Ath somewhat replaced
the contravallation. It could do so, because it stretched from the Dender River and the Burgundy
Bastion to the Brabant bastion and covered almost a third of the town’s circumference. Usually,
the first parallel was also where the attacker installed the first set of batteries to cover
the advance with suppressing fire, but again, Vauban thought this wasn’t necessary.
As intense rain had rendered the men working in the dark almost invisible, the
defenders were unaware of the quick progress. Now that the attackers were within range of the
garrison’s guns, they switched to what is known as sapping, which means approaching the fortress
in zigzag lines. With this step 6 began, the advance to and construction of the second parallel
(Step 6: Sapping and Construction of the second Parallel). This was dangerous and hard work. Layer
by layer crawling sappers removed the earth and heaped it up towards the fortress. This way, the
saps were deepened and broadened little by little until a man standing upright was fully covered
and artillery pieces could be hauled along them. Just before the point at which the enemy could
shoot along a trench, it was cut back, which caused the trenches to form the characteristic
zigzag shape. If done well, losses were usually negligible during this process, even despite heavy
bombardment. At Ath the second parallel could be dug after only two days, about 300m away from
the counterscarp, the outer side of the ditch. The ever-approaching network of trenches was
a visible noose tightening around the fortress which forced those defenders still hidden
in the grass to retreat to the covered way. Now, the garrison really took to the guns.
Relentlessly, they were thundering at the trenches. As the saps approached the walls
and came within reach of the covered way musketry joined the infernal orchestra.
Vauban told his men to persevere. Soon, he would bring his own artillery in
position and silence the defenders. It was rather an exception that a besieging
army waited until the second parallel to put up its batteries but it seems like the master
of siege craft knew exactly what he was doing. Jean-Baptiste de Vigny the commander
of the artillery was itching to return fire when on 25 May he finally received
orders to bring the guns to the front. He installed his guns in eight batteries, each
shielded by massive breastworks (Map4). On 27 May they fired their first roaring volley.
For now, their task was to prepare the attack on the covered way by smashing through the
palisades on top of the glacis, an artificial slope just outside the ditch, and to clear the
infantry off the covered way and the ravelins. This was to prepare step 7, the advance to the
glacis and the construction of the third and final parallel (Step 7: Constructing the third
Parallel). 36 guns (Map4 Batteries A-F) deployed ricochet fire. The historian John Lynn
explains that this was a mode of fire developed by Vauban and for the first time used
on full-scale at Ath. When using ricochet fire, the gunners didn’t load their pieces to the
max so that the balls would be lobbed over the parapets and bounce along the covered way and the
ravelins’ edges, maiming those positioned there. This took a heavy toll on the defenders
and forced them to take cover. Because of that their muskets and artillery fire
decreased dramatically. In addition, two mortar batteries (map4 1&2) bombarded the Cambron,
Brabançon, and Recollets ravelins from 28 May. This suppressed the defender’s fire almost
completely and allowed Vauban’s workers to drive the saps forward rapidly. Within three days
they advanced to a couple of meters of the covered way (opposite the Brabançon ravelin and the Namur
and Limburg bastions on either side of it). There, about 30m from the covered way,
the third parallel was usually installed to establish a secure
position very close to the town. But the extraordinary success of the artillery
led Vauban to forego this too. Instead, he simply had small redoubts built to shelter groups
of grenadiers, the shock troops of the time. At this point he also brought
another innovation of his into play: the so-called cavaliers de tranchée. These were
raised fighting platforms from which musketeers could enfilade the defenses and bring the work
of the ricochtet fire to perfection. However, there wasn’t much to perfect, as became clear
when a small scouting party crawled to the top of the glacis – the covered way was almost
completely abandoned. This clearly shows how effective Vauban’s ricochet fire must have been.
This made step 8, the conquest of the covered way, hitherto usually the costliest phase of a siege,
a giveaway (Step 8: Conquest of the Covered Way). The scouts immediately sent for support and
by dawn the French had seized the covered way. They only met a few surprised
defenders in the redoubts. Throughout the next days, the French workers
turned the covered way around by including it into their system of trenches and by building a parapet
facing the city wall. They were met by another hailstorm of lead and stone from the ramparts.
It was too late, however. The earth heaped-up by the workers covered the attackers already, so
that a mere three were killed and eight wounded. Catinat rejoiced over the ease at which the
covered way had been taken. But when Vauban inspected the works personally to prepare step 9,
the attack on the outworks (Step 9: Attack on the Outworks), a musketball pierced through a pile
of sandbags and hit the engineer’s collarbone. Immediately, Catinat’s joy was blight with worry
for his friend and engineer. Vauban had a severe wound, but he shrugged off medical attention
- he was used to takinge a hit from time to time after all. He had the workers expand the
lodgements all along the covered way and dig tunnels through the glacis to prepare the attack
on the Brabançon ravelin. When they broke through at the very bottom of the ditch, they began to
build fascine bridges to cross the moat. Meanwhile the artillery was rearranged (Map5) and two new
ricochet batteries (G&H) were built sideways to enfilade the neighboring ravelins. In addition,
Vauban had two breaching batteries (J&K) installed on the top of the glacis. Now, mortar bombs
rained down on the defenders, ricochet shots denied them any cover and the heavy guns of the
breaching batteries banged against both faces of the ravelin. On 31 May the walls crumbled and
the fascine bridges in the ditch were ready. When one of the mortars hit the sluice gate which
was retaining the water, the ditch went dry within hours as well. The time for an assault had come.
In thick gun smoke a forlorn hope of grenadiers was charging through the ditch, fighting its way
up the breach and pushing back the defenders. Within minutes they established a lodgment on
top of the ravelin, which gave them the necessary cover to repulse several attempts to recapture it.
Only after a long struggle, the seventy remaining defenders retreated to a redoubt at the back of
the outwork. They were cut off from the town and completely surrounded. With no hope for help and
no way to retreat, they surrendered on 3 June. Now the ravelin was turned around as well. Roeux
and Anhalt-Zerbst could only watch as the French were digging trenches and building a gallery to
the tenaille, a defensive screen in the ditch, and the Brussels gate behind (Map6). But
Vauban’s major objectives were the Namur and Limburg bastions. The breaching batteries
for that had long been ready (M&N) and were firing at the sturdy bastion walls.
Opening a breach in the main wall or the bastions was step nr. 10 (Step 10: Make
a Breach). The salvoes of breaching batteries usually first targeted an imaginary line
just above the ground to weaken the base, then moved in a vertical line upward, placing
ball above ball until they reached the upper end. This procedure was slow but very effective.
Within two days the wall began to crumble. The defenders rushed to the spot to repair the
damage but continuous fire from the batteries made the interior of the bastions a field of
death (Map6). Fewer and fewer dared to come out so that musket fire from the town ramparts
diminished from hour to hour. As the threatening breaches grew larger, the helpless defenders lost
hope. When they also heard news that the 140’000 Frenchmen in the surroundings had turned away a
half-hearted relief attempt by King William III of England, they knew they were on their own and
they realized they were fighting a lost fight. Catinat and Vauban in contrast, were
in high spirits. Their biggest concern was that peace might be concluded before
they concluded their siege. Vauban said: “things are going marvelously […]. I see
with great pleasure that I know their works better than they do. It is also true, and
I can say this without being a braggart, that never has a place been attacked with
as much art and speed at the same time.” On 5 June time had come for the last step, the
general assault (Step 11: General Assault). The breaches were wide enough. Vauban and
Catinat themselves came forward to have a look at the situation. Twenty companies
of grenadiers were readied for this task. But before Catinat could give the order to
attack, a white flag appeared over the walls. In the same night still, terms were agreed on and
what little remained of the garrison left the town on 7 June. While the defenders had suffered an
unknown but certainly large number of casualties, the French merely mourned 50 dead and 250
wounded. This was extraordinary, as the attacker usually suffered tremendous casualties,
especially before the arrival of Vauban’s methods. Also, the fortress had been taken in a
record-breaking time of just two weeks and with much fewer resources than expected. The
siege of Ath showed just how effective Vauban’s methods could be when properly executed. Not
even a cutting-edge bastion fort could put up with it. The siege of Ath became a showpiece both
for generations of engineers and history buffs up to this day. Vauban, the creator of the method
himself, had demonstrated masterfully how to lay siege in in the age of Louis XIV. If you follow
his methods, any fortress will surrender to you. Our videos take a lot of time to research and
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