Prince Louis of France had invaded England in the spring of 1216, having been invited to do so by some of the English barons: King John had agreed to Magna Carta but subsequently reneged on it, and now they sought to overthrow him and install Louis in his place.
To start with Louis had enjoyed great success, but in October 1216 John died, and a number of the magnates took the opportunity to change sides and throw their support behind John’s son and heir Henry, then aged 9. Forces loyal to Louis were defeated at the Battle of Lincoln in May 1217; however, Louis himself was at Dover with half his army, so all was not yet won or lost. He returned to London to consolidate and plan, and awaited reinforcements from France.
The French fleet, of ten large ships carrying men and horses and some sixty small supply vessels, set off from Calais. It was commanded by a notorious figure known as Eustace the Monk, a pirate who had terrorised English coastal areas for many years before throwing in his lot with Louis. If the ships full of reinforcements were to reach London and join up with Louis’s existing forces, he would probably have sufficient resource to carry the day; England would be ruled by King Louis I rather than King Henry III.
Sandwich is today several miles from the coast, but in 1217 it was a sea port, and William Marshal, young Henry’s regent, had called all the nobles who were loyal to the young king to assemble there to form an army that would take to the sea: it was imperative that the ships be stopped before they could land, so that the two parts of the French army could not unite. As an added incentive, Marshal promised his lords any plunder they could take from captured vessels.
The French ships initially sailed towards Dover as they crossed the Channel, but they then turned; on the morning of 24 August 1217 they could be seen sailing northwards, parallel with the coast, with the idea of rounding the Isle of Thanet and sailing up the Thames to London.
The English fleet of eighteen large and twenty smaller vessels left Sandwich as the French ships were passing. To start with they headed out to sea, into the wind (which was blowing from the south-east), and passed behind and to the south of the French; it looked as though the invaders had made it past the danger, with a clear sea between them and the mouth of the Thames, and they started to celebrate.
However, they had not taken into account the skill of the English sailors: by dint of excellent seamanship their ships came swiftly about and then approached the French at speed with both the wind and the sun behind them. Taking advantage of the wind, the English launched volleys of powdered lime at the French before the ships engaged, blinding and choking those on board so they were unprepared for the brutal attack that would follow.
The first vessel to reach the French was one owned by Earl Warenne. It caught up with the French command vessel, known as the ‘great ship of Bayonne’, which was so loaded down with men, horses, baggage, treasure and the pieces of a trebuchet that it was barely out of the water, and rammed it. Warenne’s ship was followed by a large cog belonging to the regent – who was not on board, having remained on shore – that sat higher in the water than the French ship, thus allowing the English to rain down arrows and crossbow bolts on their already incapacitated opponents.
Grappling hooks were thrown; the ships were lashed together; English knights and foot soldiers poured across. The situation was replicated across the fleet, the rigging of the French ships being cut so they became unmanoeuvrable and easily boarded. The bloodiest encounter took place on the command vessel, where the English carried the day in brutal hand-to-hand fighting, hacking their way across a deck so crowded that there was barely room to swing a sword.
The French common soldiers and sailors were massacred. ‘They lost no time at all in killing those they found on board and throwing them into the sea as food for the fish’, says the History of William Marshal; the sea turned red. A group of bloodthirsty men from the English fleet did attempt to kill the knights as well, but they were saved by the English lords for ransom – they hadn’t forgotten the regent’s promise of monetary gain.
Eustace the Monk, ‘the wicked pirate’, was dragged out from where he was hiding in the depths of the ship’s hold; he did make a huge ransom offer but must have known his life would be forfeit. The History of William Marshal says that he was offered the choice of being beheaded on the trebuchet or beheaded on the rail; nobody knows what his answer was, but the sentence was carried out and his severed head was later paraded on a spear around the towns of the south coast that he had terrorised for years.
The outcome of the Battle of Sandwich was the Treaty of Lambeth, finalised three weeks later, by which Louis agreed to relinquish his claim to the throne in return for a huge payment of 10,000 marks (£6,667) of silver. He sailed back across the Channel at the end of September 1217; he would never set foot in England again, but when he later assumed the throne of France as Louis VIII he would fight successfully against the English in his own realm as he sought to expel them from French soil. But the Channel would henceforward remain an insuperable barrier: England had gained a reputation for naval supremacy that it would never lose.
By C.B. Hanley