in north Nottinghamshire they surrendered the castle at 10 o'clock on 1 October 1645. The garrison was then 10 officers and 90 men with two of the men called "seniors" implying that they were professional soldiers rather than just non-commissioned officers. They also surrendered 100 muskets, 50 pikes, 20 halberds, 150 swords and two barrels of gunpowder: no pieces of artillery are mentioned. As a result of this capitulation, only Bolton Castle in Wensleydale and Skipton Castle remained in Royalist hands in Yorkshire, but Sandal "was the most resolute of all the three northern garrisons" and its fall caused great rejoicing among the parliamentarian forces. By the siege's end, it was a ruin. The following year, Parliament ordered that it be made untenable. The castle The castles built by William the Conqueror's followers were self-sufficient strongholds, some of which were tax-gathering points, some controlled the larger towns, river crossings or passes through hills. Two castles were built near Wakefield, one at Lowe Hill on the north bank of the Calder and Sandal on the south bank. The first castles were probably started and completed in the early 12th century by William de Warenne, 2nd Earl of Surrey after he had been granted the manor of Wakefield by Henry I. Sandal and Lowe Hill were motte-and-bailey earthwork castles with wooden towers on the mound and baileys with timber palisades and deep ditches. Sandal is built on a natural sandstone ridge, the Oaks Rock. The motte was raised to with the deep moat surrounding it. Only Sandal survived and during the 13th century the keep, curtain wall and other buildings were rebuilt in stone, probably started by either the sixth or seventh Earls Warenne. Timber motte and bailey castles were often converted into stone if they were in use for long periods; Sandal is a particularly good example of this. The stone keep was circular with four towers each four storeys high; two of them close together formed a gatehouse, and the east tower contained a well, deep. The double-walled keep would have had guardrooms, storerooms and servants' quarters on the ground floor, the main hall above and private apartments on the second floor. The tower rooms had garderobes, (lavatories) that discharged on the outer walls of the keep. The curtain wall was high with a wall walk along its length, it enclosed the bailey and crossed the moat twice to reach