The Red Saint by Warwick Deeping

The early days of December found Earl Simon lodged at Southwark, while the King and his men prowled to and fro in Kent, coveting England's sea gate, Dover, that the barons had taken in the summer. Earl Simon had no great gathering with him in Southwark, for he had London at his back, an ant's nest into which the King would not venture to thrust his spear. There had been much bloodshed and violence in the land, and it was De Montfort's hope that Henry would show some wisdom now that he had seen many of his great lords in arms against him. A truce had been mooted, with Louis of France to judge between the two parties. Yet no man trusted Henry, because of his fickleness and his foolish cunning, and because of the favourites who had his ear.

Henry had hated the Londoners with exceeding bitterness since they had pelted his Queen from London Bridge when she had sought to escape to Windsor in the summer. They had thrown stones and offal at her barge, and the King, and Edward his son, talked of the blood of the city as though it were the blood of swine. It was even said that they had sworn upon relics to make a slaughter there that should be remembered for many years. Yet a number of the wealthier merchants were for the King, partly because they hated the lesser men and the mob, and partly because they had taken bribes. There was treachery afoot of which Earl Simon knew nothing, nor had he any foreshadowings of the peril that was near.