The citizens and the barons now entered into solemn covenant to stand by each other "saving however their fealty to the king." A constable and a marshal were appointed to command the city force, which was to stand prepared night and day to muster at the sound of the great bell of St. Paul's. The manor of Isleworth, belonging to Richard, King of the Romans, the king's brother, was laid waste, and Rochester besieged, but, disturbances again breaking out at home, Leicester had to hurry back to restore order and prevent the city being betrayed to the king's son.(249)
In May the earl set out again with a force of Londoners(250) to meet the king, who was threatening the Cinque Ports. In the early morning of the 14th he came upon the royal army at Lewes. Prince Edward himself led the charge against the Londoners--he had not forgotten the insult they had recently offered to his mother--and succeeded in driving them off the field. They scarcely indeed awaited his onslaught, so unpractised in warfare had they become of recent years, but turned their backs and sped away towards London, followed in hot pursuit by Edward. When he returned he found that, owing to his absence, the day was lost, and that his father and brother had been made prisoners.(251) In spite of his own success, he also had to surrender.
The barons returned to the city in triumph, bringing the king and Richard, king of the Romans, in their train. Edward had been placed in custody in Dover Castle, pending negotiations. Henry was lodged in the Bishop's Palace, whilst Richard was committed to the Tower. An agreement was drawn up which secured the safety of the king, and left all matters of dispute to be again referred to arbitration.(252) This treaty formed the basis of a new system of government, and led to the institution of Simon de Montfort's famous Parliament.
The short respite--for it proved to be no more--from civil war was welcomed by the Londoners. The city had been drained of a large part of its population in order to increase the Earl of Leicester's army, and business had been seriously disturbed. For the past year no Court of Husting had been held, and therefore no wills or testaments had received probate; whilst all pleas of land, except trespass, had to stand over until the country became more settled.(253)