The history of this transaction is as follows:-- In 1202, Poitou had risen against John Lackland, of England, Duke of Aquitaine and Count of Poitou, taking the part of young Arthur, whom he had just made prisoner at Mirebeau.

The town of Poitiers had closed its gates against John, warned by the example of Tours, which he had lately sacked and burnt.

The King had posted his troops in the towns of Limousin and Perigord, with orders to his captains to endeavour to take Poitiers by surprise.
The mayor of Poitiers had a secretary who was both cunning and avaricious, who, bribed highly by the English, had consented to deliver the town to them.

Accordingly, on Easter eve, a party of the enemy, under false colours, arrived at the Porte de la Tranchee; the secretary repaired instantly to the chamber of the mayor, to which he had access, expecting, as usual, that the keys would be found there; but, to his surprise, they were removed, nor could he find them in any other accustomed place.

The traitor hastened to inform the English of the fact, by throwing a paper to them from the ramparts, requesting that they would wait till four o'clock in the morning, when he should be able to execute his purpose.