From the Clyst many villages take name, as Clyst St. Lawrence, Broad Clyst, Honiton Clyst, Clyst St. Mary, and Clyst St. George. The last two are near Topsham and were the scene of a struggle during the Prayer Book Riots. In Devon the insurrection started on Whit-Monday, 1549, at Sampford Courtenay, the day following that on which the Act altering the Church service came into force. The people of the village insisted on the priest saying the usual mass instead of the prayers given in the appointed Book of Common Prayer. The rebellion spread rapidly, and ten thousand men marched on Exeter, with a good sprinkling of old Devon families in their ranks; but they were undisciplined and were quickly dispersed by Lords Grey and Russell. Although demoralized, the rebels assembled at Clyst St. Mary, which they fortified. From here they sent word to the king demanding the continuance of their former Church services, but the king's reply was an army under the command of Lord Russell, and after a brief resistance Clyst St. Mary was burned to the ground and the rebels scattered, to be again beaten and their leaders taken on Clyst Heath. The vicar of St. Thomas's Church, Exeter--at that time situated outside the walls--one of the leaders, was hanged from his own church tower. On the west bank of the Exe, almost opposite Topsham, are Powderham Park and Castle, the latter supposed to have been built originally by Isabella de Fortibus. It has been conjectured, and is indeed highly probable, that a fortified building or earthwork of some kind occupied the site at a much earlier date, possibly as early as the Danish invasions. In later times the manor belonged to the Bohuns, and it came into possession of the Earls of Devon through the marriage of Margaret de Bohun with Hugh Courtenay, the third earl. In 1645 the castle was besieged, unsuccessfully, by Fairfax, but in the following year it was taken by Colonel Hammond. Until about the middle of the eighteenth century it remained strongly fortified, but at that time it was subjected to many alterations. The oldest part of the present castle dates from the time of Richard II, but the whole fabric has undergone so many restorations that it presents a great variety of architectural styles. The fine modern hall contains a fireplace which is a replica of the one at the Palace, Exeter. The park is a delightful stretch of greensward, studded with ancient oaks, and it extends for many miles around the building. In one corner of the park is the little church of St. Clement, a Perpendicular building of red sandstone, and within which are several memorials of the Courtenays. These include a recumbent effigy popularly supposed to represent the renowned Isabella, although this lady is known to have been buried at Bromnor Priory, Wilts. It is the opinion of some authorities that this monument is a cenotaph to Elizabeth, daughter of Edward I, and wife of Humphrey de Bohun, whose daughter, Margaret, married Hugh Courtenay.