Crusader Fleets: A Missing Ingredient

By Steve Tibble

We tend to associate the Crusaders with all the bold, visually striking, images of medieval warfare. Charging knights and crossbowmen. Castles and siege towers. What we do not often think of is sailors and fleets.

And there is a very good reason for that – none of the Crusader States ever had a navy.


This was a problem. Taking a coastal town without naval support was always difficult and rarely quick. But the unremitting need to capture the Muslim coastal cities meant that it often needed to be attempted. There was sometimes no viable alternative, and a small chance of success was better than none at all. The contrasting stories of successive sieges against the same coastal cities highlight the stark difference between having naval support or not.

The Navy That Never Was

The attempts to capture Arsuf are a good example of just how depressing that process could be. By the end of 1099 the Kingdom of Jerusalem was still only connected to the West by a single port, Jaffa, which was in turn only connected to the Holy City by a narrow and dangerous corridor. If the Frankish presence in Palestine was to be sustainable, Godfrey of Bouillon, the ruler of Jerusalem, needed to expand this lifeline as a matter of urgency.


Godfrey first attempted to do so by trying to capture the coastal town of Arsuf, just 18 kilometres north of Jaffa. There was a difficult history between the Crusaders and the port, coloured on both sides by bad blood. Arsuf had arranged to pay tribute after an abortive siege in August 1099, and hostages had been exchanged to ensure that both parties kept to their agreement. The Muslim hostages had escaped from captivity, however, leaving the Egyptian garrison of Arsuf in possession of Christian prisoners (including a knight from Hainaut called Gerard of Avesnes) and little motivation to continue paying their protection money.

Despite the lack of men and ships, and the perennial Muslim threat on the eastern frontiers, the urgency of the coastal strategy meant that it still had to take priority. Godfrey had little choice but to move to besiege Arsuf again in the middle of October. The fighting turned very nasty, very quickly, even by the low standards of the time. The Fatimid troops, perhaps because of a sense of the Crusaders’ impotence, deliberately set out to goad them. This was not entirely illogical. The Frankish position was transparently weak. They had no fleet and no way of enforcing a blockade. They were reduced in numbers as many of the Crusaders had headed north, and most of the rest had returned to Europe. And the approach of winter made conditions for the besiegers even worse than usual.

Hostages and Horror

The Frankish hostages were the first to suffer, and in a manner calculated to be provocative. Some were tortured and executed. The most senior among them, Gerard of Avesnes, was strung out in front of the city walls and subjected to a mock crucifixion. In an act of gruesome theatre, the garrison ‘used ropes and chains to raise on high a ship’s mast of great length . . . stretching out his hands and feet with ropes’.

Artillery and Engines

The Crusaders spent six weeks making siege engines and catapults. Significantly, in the absence of a fleet (and hence also in the absence of naval craftsmen), the artillery they constructed seems to have played little part in the siege. Instead, Godfrey focused on the one area where he felt he could still bring his particular strengths to bear: he built a siege tower to allow his heavily armoured knights to gain access to the battlements.


The siege tower was pushed laboriously across the town’s moats and on towards the walls. Just as he thought things could not get much worse, the crucified Gerard of Avesnes found himself being used as a human shield and caught in the crossfire, as the Crusaders tried to clear the walls with archers and crossbows. Inevitably, given that he was placed at the epicentre of the Frankish assaults, ‘Gerard was shot and wounded by ten [arrows]’.

The siege tower had been covered with bulls’ hides to provide protection from projectiles and incendiary devices. The Muslims used archers and wall-mounted artillery to hinder its progress, but their most effective defence was fire. Throwing a mixture of oil and pitch which the Crusaders struggled to extinguish, they eventually set the siege tower ablaze and, just as it reached the walls, the structure collapsed.

The combination of fire and a collapsing tower, within easy range of enemy archers, made for a scene of horror that few participants forgot. The death toll was enormous, particularly relative to the size of the small Frankish army: somewhere between 50 and 100 casualties were reported. Crusaders returning to Europe spoke of ‘broken backs and necks, others’ legs half cut off, hips or arms, certain had burst intestines from the unbearable weight of the timbers; having no strength to free themselves, they were reduced to ember and ash with the timbers’. A prominent knight named Franco of Mechelen was trapped in the wreckage. His comrades were forced to stand helplessly by as he burnt slowly and very noisily to death.

Ruins of the Crusader fortress at Arsuf – photo by אור פ / Wikimedia Commons

So Close – But Not Close Enough

The assault had almost succeeded. The tower had been moved right up to the wall, and some men had already been able to jump off the siege tower and onto the ramparts. Two knights trapped on the wall were faced with an appalling choice. The tower behind them had collapsed, but to stay on the ramparts meant certain death. They both decided to jump. The knights were injured in the fall, and the Muslim defenders showered stones on their heads to help them on their way. Amazingly, and providing a stunning endorsement of the quality of Frankish helmets, both made it back to the safety of the besiegers’ lines.

The destruction of the tower and the failure of the assault had a huge impact on the morale of the army. With no navy and few men, Godfrey was faced with either repeating the same tactic (it had, after all, very nearly worked), or calling off the siege altogether.

His decision smacked of desperation and a chronic lack of alternatives rather than genuine optimism. Godfrey eventually chose to launch the same assault again, in the same manner. Much the same happened, but with even less success. Another multi-storey tower was constructed and pushed across the ditch. Catapults and archers provided covering fire but before it could get to the walls, the garrison once again managed to set it on fire. The protective hides again proved insufficient, and the blaze could not be extinguished by water.

Significantly, this time the tower seems to have collapsed before it was fully consumed by the fire, with casualties being greatest among those on the ground who were trying to put the fire out. One of the Frankish chroniclers explicitly blamed this on poor construction rather than the blaze, saying that it could not sustain the weight and ‘collapsed into pieces because of the large number of men climbing up within it’. Finding good timber for siege towers was always problematic in the Middle East, particularly the long corner timbers needed to maintain stability, and the best raw materials had inevitably been used on the first tower.


Options Without a Navy

Godfrey had finally run out of options. As was often the case, the policy objectives and underlying strategy were sound, even compelling. But they were undercut by tactical problems and a debilitating lack of resources. Without a navy, he could not enforce a blockade. With the winter weather worsening, his men were suffering more from privation than the defenders. Lacking Italian marine craftsmen, his siege towers seem not to have been of the highest quality, being neither fireproof nor sturdy. Mining does not seem to have been considered as a viable possibility.

This vicious little episode shows just how limited the choices were for a besieging army with no naval support. The Franks abandoned the siege and returned to Jerusalem in mid-December, in time for what must have been rather gloomy Christmas celebrations.

Frankish besieging forces, however well-led or well-motivated, found it extraordinarily difficult to conduct a successful siege against a coastal town which could expect seaborne relief. The ‘coastal strategy’ of focusing on the capture of the Muslim maritime cities, was clearly the correct course of action. If it was to succeed, however, the tactical implementation of that strategy was going to need careful coordination between land and naval forces.

The coronation of Baldwin I as depicted in a 13th-century manuscript – BNF MS Français 2754 fol. 1r

What a Difference a Fleet Makes

It was not until the spring of 1101 that an opportunity emerged to besiege Arsuf with naval support. A Genoese expedition to the East had become an almost annual event at this time, and their expedition of 1100–1101, consisting of 26 galleys and six other vessels, finally arrived outside Jaffa on 15 April 1101. Duke Godfrey had died shortly after the second abortive siege of Arsuf, so the Genoese were greeted by King Baldwin I, his successor. The king was naturally delighted to see them.

The sordid matter of dividing future spoils needed to be sorted out. From both parties’ perspectives, there were issues to be resolved. In the short term, there was plunder to consider, mainly the distribution of movable goods and the money that could be extracted from the taking of prisoners, either as ransom or as slaves. In the longer term, there was the bigger issue of trading rights, and establishing bases within the captured cities upon which commercial operations could be built. The king was naturally disinclined to give too much away, but it was in everyone’s interests for successful mercantile centres to be established on the coast. Once the broad principles of the expedition were agreed upon, it remained only to determine the objectives. The Genoese asked King Baldwin to choose and the king ‘decided that Arsuf should be besieged by sea and by land’.

The Christian forces arrived at Arsuf on April 26, 1101. A close siege was put in place immediately. It normally took at least a couple of weeks to build the appropriate siege engines, but the resolve of the townsfolk broke long before the work was finished. The ‘third day of the siege was scarcely at an end when the citizens of Arsuf sought to make peace with the king … and he granted them a safe conduct as far as Ascalon’.

The Key to Unlocking the Strategy

The relatively civilized conclusion to the siege, particularly given the poor relations between Arsuf and the Franks, was no coincidence. For the people of Arsuf, realizing that they were unlikely to be relieved by the Egyptian navy, it was important to end the siege as quickly as possible. Given the animosity created by the previous siege, any outcome that ended with a full-scale assault was inevitably going to lead to a great deal of unpleasantness.

Similarly, from the Crusaders’ perspective, treating Arsuf with leniency was a clear signal: we are people you can do business with and, if you submit quickly, this can all end peacefully. The coastal strategy fundamentally hinged on violence, or the threat of violence, but if it could be accomplished without unnecessary bloodshed, so much the better.

But none of this would have been possible without the missing ingredient of Frankish warfare and the crusader states – a fleet.

Dr Steve Tibble is a graduate of Jesus College, Cambridge and London University. He is a leading authority on warfare and violence in the crusading era.

His recent book The Crusader Strategy (Yale 2020) was received to critical acclaim and short-listed for the Duke of Wellington’s Military History Award. It is our current Book of the Month.

Steve is the author of  Templars: The Knights Who Made Britain (Yale, 2023) and The Crusader Armies, Yale 2018. He is a contributor to ‘The Cambridge History of the Crusades’ and ‘The Oxford Illustrated History of the Crusades’, both forthcoming in 2024. You can learn more about Steve on his personal website, or follow him on X/Twitter or Instagram.

Top Image: A 14th-century depiction of Crusaders on a ship attacking a town. British Library MS Royal 19 D. I, f.187v