But the French barons received the message with indignation; disclaimed the temporal authority assumed by the pontiff; and vowed that they would, to the uttermost, assist their prince against all his enemies; Philip, seconding their ardor, proceeded, instead of obeying the pope's envoys, to lay siege to Chateau Gaillard, the most considerable fortress which remained to guard the frontiers of Normandy.
{1204.} Chateau Gaillard was situated partly on an island in the River Seine, partly on a rock opposite to it; and was secured by every advantage which either art or nature could bestow upon it.

The late king, having cast his eye on this favorable situation, had spared no labor or expense in fortifying it; and it was defended by Roger de Laci, constable of Chester, a determined officer, at the head of a numerous garrison.

Philip, who despaired of taking the place by force proposed to reduce it by famine; and that he might cut off its communication with the neighboring country, he threw a bridge across the Seine, while he himself, with his army blockaded it by land.

The earl of Pembroke, the man of greatest vigor and capacity in the English court, formed a plan for breaking through the French intrenchments, and throwing relief into the place.

He carried with him an army of four thousand infantry and three thousand cavalry, and suddenly attacked, with great success, Philip's camp in the night time; having left orders that a fleet of seventy flat-bottomed vessels should sail up the Seine, and fall at the same instant on the bridge.