Also, after a fleet assembled by his wife, Blanche of Castile, attempted to bring him French reinforcements but was defeated off the coast of Sandwich on 24 August 1217, he was forced to make peace on English terms.

After numerous months of half-hearted attempts to reach a settlement in the summer of 1215, open conflict was unleashed amongst the rebel barons' alliance and the loyalist factions.

The contemporary document, the Annals of Waverley saw no contradiction in stating that Louis was invited to invade to "prevent the realm being pillaged by aliens."

Many nobles gathered to give homage to him, including Alexander II of Scotland, who held fiefs in England.

Gerald of Wales remarked: "The madness of slavery is over, the time of liberty has been granted, English necks are free from the yoke."

Pursuing John, Louis led his army south from London on 6 June, arriving the following day in Reigate where he found the castle abandoned.

[5] In the meantime, the King of France taunted his son for trying to conquer England without first seizing its key port, Dover.

In the meantime, Louis's occupation of Kent was being undermined by a guerrilla force of Wealden archers raised and led by William of Cassingham.

After three months spent besieging the castle and a large part of his forces being diverted by the siege, Louis called a truce on 14 October and soon returned to London.

Apart from Dover, the only castle to hold out against Louis was that at Windsor, where 60 loyalist knights survived a two-month siege, despite severe damage to the structure of its lower ward.

That was immediately repaired in 1216 by Henry III, who further strengthened the defences with the construction of the western curtain wall, much of which survives today.

In 1206, John had spent £115[a] on repairs to Rochester Castle, and he had even preemptively held it during the year of the negotiations leading up to Magna Carta, but the Charter's terms had forced him to hand it back into the custody of Stephen Langton, Archbishop of Canterbury, in May 1215.

The rebels were expecting reinforcements from London but John sent fire ships out to burn their route in, the city's bridge over the Medway.

By one of those means, the king's forces entered and held the bailey in early November, and began attempting the same tactics against the keep, including undermining the south-eastern tower.

On 25 November 1215, John had sent a writ to the justiciars saying, "Send to us with all speed by day and night, forty of the fattest pigs of the sort least good for eating so that we may bring fire beneath the castle".

Pierre des Roches, Bishop of Winchester, and a number of barons rushed to have the young Henry crowned as King of England.

The French camp, set up outside Dover Castle in anticipation of the new siege, was attacked and burned by William of Cassingham and Oliver fitz Regis just as the fleet carrying the reinforcements arrived.

The principal provisions of the treaties were an amnesty for English rebels but the barons who had joined Louis had to pay the French prince 10,000 marks to expedite his withdrawal.

Louis surrendered the few remaining castles that he had held and exhorted to his allies, Scottish and Welsh troops under Alexander II and Llywelyn the Great respectively, to lay down their arms.