A monk, a pirate, an outlaw and a commander of ships, he fought for both the English King John and his adversary, Phillip ll of France.
The younger son of a lesser noble family, he was born in Courset near Boulogne. As a young man he joined the Benedictine order belonging to the monastery of St Vulmar, which was based nearby in Samer. While there, it is said that he gained a reputation as a gambler and user of foul language. (This no doubt, earned him the tittle of "The Black Monk").
When Hainfrois de Heresinghen allegedly murdered his father in 1190, Eustace left the monastery determined to exact revenge on the killer. The two men did eventually fight a duel, though they did it by proxy, each man appointing another to fight in his place. To Eustace’s disgust, Hainfrois was declared innocent, after his champion won the duel.
Eustace was appointed seneschal to Renaud, the Count of Boulogne, in 1204 but lost the post soon afterwards. He was later outlawed and turned pirate after attempting many times to exact revenge against both Hainfrois and the Count.
Attracting others of his kind Eustace soon had a squadron of ships at his command and made a living from pillaging both French and English coastal towns and villages. Like many pirates Eustace was a mercenary and he and his men were available for hire. Somehow in 1205 he came to the notice of King John, was hired, given charge of thirty galleys and put to work attacking the coastal towns of Normandy. In September of the same year Eustace sailed with his fleet, evicted the French from Jersey and took possession of the Channel Isles (By 1207 they were being called Les Isles Anglo-Normandes)
For the next six years Eustace seemed settled in the service of King John. He was even said to have build a home in London and sent his daughter to a school for the nobility. Then suddenly in 1212 he switched to the side of France taking five of the king’s ships with him. (And no doubt being richly rewarded for his troubles)When he switched sides the English seized his bases in the Channel Isles and in retaliation he attacked Folkestone. In an abortive attempt, he also tried but failed to recapture the islands of Jersey and Guernsey. But he did manage to seize Sark and leave a force of men there.
In 1214 the warden of the islands, Philip d’Aubigny who was appointed by King John, recaptured Sark and sent Eustace’s men in chains to Winchester. At the outbreak of the English civil war in 1215 Eustace helped to transport and protect the troops belong to Prince Louis of France when he invaded southern England to stake his claim on the crown. By 1216 Eustace was back in the Channel Islands and he and his brothers were once more in control.
On the 24th of August 1217 Eustace sailed with a French fleet bringing reinforcements to Prince Louis. The fleet consisting of ten large ships, each carrying in the region of one hundred and twenty-five knights and seventy smaller ships filled with supplies. As they sailed past Sandwich the English fleet emerged and the battle began. The English were outnumbered, but disaster was avoided when a cog under the command of Phillip d’Aubigny, began to throw pots of powered lime onto the deck of the French flagship, the resultant cloud effectively blinded the French knights and they surrendered. When the ship was boarded and searched, Eustace was discovered below, brought on deck and executed. Later his head was stuck on a lance and paraded through Canterbury and Dover.
