had become royalist; the marshal and Hubert de Burgh held Sandwich, so that the long voyage up the Thames was the only way of taking succour to Louis.  Next day the old earl remained on shore, but sent out Hubert with the fleet.  The English let the French pass by, and then, manoeuvring for the weather gage, tacked and assailed them from behind.[1] The fight raged round the great ship of Eustace, on which the chief French knights were embarked.  Laden with stores, horses, and a ponderous trebuchet, it was too low in the water to manoeuvre or escape.  Hubert easily laid his own vessel alongside it.  The English, who were better used to fighting at sea than the French, threw powdered lime into the faces of the enemy, swept the decks with their crossbow bolts and then boarded the ship, which was taken after a fierce fight.  The crowd of cargo boats could offer little resistance as they beat up against the wind in their retreat to Calais; the ships containing the soldiers were more fortunate in escaping.  Eustace was beheaded, and his head paraded on a pole through the streets of Canterbury.

[1] This successful attempt of the English fleet to manoeuvre for the weather gage, that is to secure a position to the windward of their opponents, is the first recorded instance of what became the favourite tactics of British admirals.  For the legend of Eustace see Witasse le Moine, ed.  Foerster (1891).

The battle of St. Bartholomew’s Day, like that of Lincoln a triumph of skill over numbers, proved decisive for the fortunes of Louis.  The English won absolute control of the narrow seas, and cut off from Louis all hope of fighting his way back to France.  As soon as he heard of the defeat of Eustace, he reopened negotiations with the marshal.  On the 29th there was a meeting between Louis and the Earl at the gates of London.  The regent had to check the ardour of his own partisans, and it was only after anxious days of deliberation that the party of moderation prevailed.  On September 5 a formal conference was held on an island of the Thames near Kingston.  On the 11th a definitive treaty was signed at the archbishop’s house at Lambeth.

The Treaty of Lambeth repeated with little alteration the terms rejected by Louis three months before.  The French prince surrendered his castles, released his partisans from their oaths to him, and exhorted all his allies, including the King of Scots and the Prince of Gwynedd, to lay down their arms.  In return Henry promised that no layman should lose his inheritance by reason of his adherence to Louis, and that the baronial prisoners should be released without further payment of ransom.  London, despite its pertinacity in rebellion, was to retain its ancient franchises.  The marshal bound himself personally to pay Louis 10,000 marks, nominally as expenses, really as a bribe to accept these terms.  A few days later Louis and his French barons appeared before the legate, barefoot and in the white garb of penitents,