The citizens, in the reign of John, suffered considerable loss from the depredations of the Dauphin, who had been invited from France to assist the barons. In 1272 a riot between the monks and the citizens caused the burning of the priory. The terrible plague, called the black death, that occurred between 1348 and 1349, destroyed two-thirds of the population. The city no sooner was beginning to recover from this terrible visitation than one of its residents, John Listher, a dyer by profession, incited an insurrection called the Norfolk Levellers. They managed in 1381 to do much damage before the rebellion was quelled by the Bishop of Norwich, who defeated Listher and had him executed. From Henry IV. the citizens received permission to be governed by a mayor and sheriffs in 1403, and Norwich was made a county of itself. But in spite of it all the city severely suffered: what with the continued dissension between the monks and the citizens, when the monastic buildings were burnt down, and the tumults by tradesmen all too ready to lay aside their tools and follow some hare-brained leader with a grievance, and later on, after the peaceful period of Elizabeth, the Civil War. The most notable insurrection was that conducted under the reign of Edward VI. by a tanner, Robert Kett, and his brother William. Under the pretence of resisting the "enclosure of waste lands," they contrived to excite a most formidable rising. They seized upon the palace of the Earl of Surrey, and, converting it into a prison, confined many of the aristocracy. They then encamped upon Mouse-hold Heath, where eventually they were routed by the army under the Earl of Warwick in 1549. The two brothers were taken prisoners, Robert being hanged on Norwich Castle, and William suffering a like penalty on the steeple of Wymondham church, the parish from which they had both come. During the reign of Elizabeth a large body of Dutch and Walloons settled in Norwich, and introduced among many other articles the manufacture of bombazine, for which the city soon became noted. These refugees were Protestants, who had sought an asylum in England to escape the persecution of the Duke of Alva, and though many Roman Catholics and even some of the Protestants were unwilling martyrs to the stake at Norwich during this same reign of Elizabeth, the city no doubt appeared to these exiles to offer a better chance of life than that in the Netherlands. By the year 1582 their numbers had increased to five thousand. The Queen, who had encouraged and protected these emigrants, thus laid the foundation of the commercial and manufacturing prosperity of the town, as she had done elsewhere, and on her visit to Norwich was sumptuously fêted. But the Civil War in Charles I.'s reign did much to upset trade in Norwich. It was held by the Parliamentarians, who seem to have got out of control. The Cathedral was barbarously defaced, all its plate and ornaments looted, and the Bishop's Palace greatly damaged.