It was on St Bartholomew’s Day, 24 August 1217, that a French fleet of around eighty vessels sailed before southerly winds ‘in a formation so tight and orderly’ up the Kentish coast towards the Isle of Thanet and the Thames estuary. It was bound for London, held by the Dauphin Louis of France. ‘That day was a very fine and clear one and it was possible to see far out to sea,’ said the poem dedicated to the deeds of William the Marshal. So there can be little doubt that the French flotilla was observed from the White Cliffs north of Dover – perhaps not by William himself, as the thirteenth-century English chronicler Matthew Paris suggests, but certainly by someone. According to the poem, William had made sure of it as soon as he had learned of the convoy’s imminent departure from Calais a few days before, ‘for he knew beyond any doubt that, if that French fleet out there was able to put to shore, then the game would have disastrous results and England would be lost’.
The outcome of the First Barons’ War and the concomitant invasion of England by Louis, heir to the throne of France, was very much in the balance. While Louis had suffered a devastating setback when his forces lost Lincoln in May, he remained entrenched in London with his army still intact, including ‘the majority of the barons’. Moreover, King John’s heir, Henry III, was only nine. William, his protector, needed time to garner support and shore up the young king’s grip on government – something that significant reinforcements from France would likely curtail. The northern nobility and the so-called ‘Barons of the Cinque Ports’ had already demonstrated a dismaying propensity to support whichever side seemed to be winning – and, with reinforcements, that could be Louis and the rebel lords. William understood that the best chance for the royalist cause was to preclude the French fleet from ever reaching its destination. To that end, he had beckoned the ‘Barons of the Cinque Ports’ to Romney on 19 August and bade them face the French fleet in return for the restoration of their privileged status and all the plunder they could win. Although still bitter over King John’s overbearing treatment in the past, they agreed, and a watch was set.
That said, when the French armada first appeared, the sailors of the Cinque Ports were daunted. The Dauphin’s wife, Blanche of Castile, had gathered a formidable fleet. The History of William Marshal estimated it at 300 vessels, but the figure of eighty given by both Roger of Wendover, a contemporary English chronicler, and the anonymous thirteenth-century Histoire des Ducs de Normandie et des Rois d’Angleterre (‘History of the Dukes of Normandy and of the Kings of England’) is probably closer to the truth. Of these, ten were great ships, containing most of the knights (around 125, estimates English historian Henry Cannon) and men-at-arms. The remainder were smaller transports, carrying equipment and provisions. ‘Their pilot and commander’ was the almost mythical mercenary mariner Eustace the Monk. A former friar at the Benedictine Abbey of St Vulmer at Samer near Boulogne, he had renounced his vows in order to fend for his family when his father was murdered. He served as seneschal for Count Reynaud of Boulogne until false accusations from his father’s murderer prompted him to flee, eventually reaching England, where he took up employment with King John. For a number of years, basically between 1205 and 1212, he commanded a small flotilla which ravaged French interests in the English Channel, ultimately setting himself up in the Channel Islands. He switched allegiance to King Philip II Augustus over John’s alliance with Reynaud of Boulogne just before the First Barons’ War broke out. He then raided the south and east coasts of England, including the Cinque Ports, earning the reputation cited by Roger of Wendover as ‘a most disgraceful man and a wicked pirate’. He was also a highly competent commander, for which the sailors of the Cinque Ports realized they had no counterpart – that is, at least until Hubert de Burgh showed up at Sandwich with ships from Dover to stiffen their resolve.
William had wanted to assume command of the English fleet himself, but he must have been nearly seventy at the time and his entourage convinced him that the king would be better served if he remained ashore to direct the overall defence of the realm. Thus, it fell to Hubert de Burgh as Justiciar of the kingdom to command the fleet which comprised ‘sixteen well-armed ships, not including some small ones which accompanied them to the number of twenty’, reported Matthew Paris, to whom Hubert provided an eye-witness account many years later. With him were two prominent knights from the garrison at Dover: Henry de Turville and Richard Suard. They embarked upon what the History of William Marshal described as ‘a magnificent ship equipped with a fine crew’, which must have included sailors from the Cinque Ports. Richard FitzJohn, the bastard son of King John, took charge of another. Philip d’Aubigny apparently assumed command of one as well, while William had his own men-at-arms crew what his History specifically called a ‘cog’, probably fitted with at least a sterncastle. This may, in fact, have been Hubert’s ship, but the various accounts are confused in this regard. Both Roger of Wendover and Matthew Paris claim the English also had galleys with ‘iron rostra’ or rams, but this surely was an imaginative invention based upon classical precedents.
The flagship of the French fleet was designated ‘the great ship of Bayonne’ by William’s History, which also said that ‘it housed the king’s treasury’. On board with Eustace were thirty-six highly placed knights; the most exalted was Robert de Courtenay, uncle to the queen of France. He actually held precedence over Eustace. In addition, there were Ralph de la Tourniele and William des Barres, two of Philip’s finest. Three other great ships carried the rest of the knights and the remaining six transported most of the men-at-arms. The History claims that the vessel from Bayonne was in the van, but this would have been highly unlikely. The History of William Marshal itself explained why: ‘the monk’s ship was greatly overloaded and could only sit so deep down in the waves that the water almost washed over her, the reason being that it carried the siege engine (a trebuchet) and a very heavy load besides, including the fine horses shipped for Louis’. In all probability, Eustace’s ship lagged last, a circumstance which would go a long way towards illuminating why the battle unfolded as it did.
As the French fleet streamed northwards with a following wind through the Downs past Sandwich, Hubert de Burgh led his squadron out luffing into the wind, seemingly to intercept it. Instead, he merely feigned an attack and continued due southeast towards Calais, passing astern of the French flagship. Eustace then assumed that Calais was the objective and dismissed it as a foolish assault on a well fortified port. By this time the French fleet, sailing in close order, had covered much of the distance to the Isle of Thanet and Eustace was inclined to simply stay the course. Unfortunately for the French cause, he was not in charge. Robert de Courtenay, believing the outnumbered and outmanned English vessels which had approached so slowly as they close-hauled into the wind were easy prey, ordered the ship to turn and engage. While Eustace’s morality and loyalty could be questioned, his seamanship could not. He must surely have sensed that his fate had been sealed the second his ship came about. What Hubert de Burgh was actually doing was acquiring the ‘weather gage’: the upwind position. Moreover, since it was morning, the sun must have been shining out of the east. Hubert now turned to put both the wind and the sun at his back. The crew of ‘the great ship of Bayonne’, on the other hand, found themselves in a ponderous, overburdened vessel stalled to windward with the sun in their eyes facing a line of English ships bent upon their destruction.
The first of the English great ships to reach the slow, barely manoeuvrable French flagship was evidently that of Richard FitzJohn. The French resisted desperately but three other English ships soon joined the fray, one of which was the cog containing William Marshal’s men-at-arms. Meanwhile, the rest of the French fleet, pushed by the southerly winds, must have continued on course to the north for some time before realizing that their flagship was engaged. The English cog, lightly loaded and high in the water, quickly turned the tide of battle. The usual fusillade of missiles included pots of quicklime hurled from the castle of the cog down onto the deck of ‘the great ship of Bayonne’. Several of the contemporary sources testified to the tactic, which makes perfect sense, given the wind and height advantage. Its crew blinded, the French flagship was easily boarded by William’s men, who jumped from the cog down onto the deck, scattering the now hapless and helpless French knights. It was probably all over quite quickly. All thirty-six French knights were taken prisoner.