French victory The siege of Château Gaillard was a part of Philip II's campaign to conquer John, King of England's continental territories.

Instead he attacked a number of lesser castles in the surrounding area, effectively isolating Château Gaillard and ensuring that his operations were not threatened by nearby forces.

They could come out to make local counterattacks, but for the most part they had to simply remain within the defenses and try to counter the moves that Philip made.

With his communications secure and access to the castle now gained, Philip began the work of reducing its defenses so if wars happened they would fortake in easier battles for themselves.

Meanwhile, a land force under William the Marshal was to attack one part of the French army which, with their backs to the river and unable to retreat, could be destroyed.

The land attack was completely successful at first, but the French were able to retreat over the bridge of boats, as the river assault had not arrived in time.

In addition to troops and crews, the boats were heavily laden with supplies for the garrison, and took much longer than planned to row upstream against current and tide.

[citation needed] Even in the medieval period, the successful application of technology allowed a small force to achieve results out of proportion to the size of the unit.

The tool in this case was Greek fire, a mixture of naphtha, pitch, and other ingredients that burst into flames when exposed to air.

Strapping a number of clay canisters of flammable material to his body, a Frenchman named Galbert was able to swim to the island behind the castle and place his charges.

He ordered that the trenches he dug to defend the camp and that a "covered way" be set up to allow his men to approach the castle without danger.

The result was several hundred people ended up trapped between the besiegers and the castle as siege engines and archers exchanged fire over their heads.

King John of England made another attempt to break the siege, this time by raiding Brittany to draw off the French.

They built belfries, mobile structures designed to protect men while they used rams or other equipment to attack walls and gates.

Château Gaillard's commander, Roger de Lacy, returned to England to begin work reinforcing his own castle at Pontefract.

It is likely that the humiliation of Château Gaillard played a part in the decision of English barons to challenge King John.