Passage: Melbourne is a town in South Derbyshire close to the River Trent, which may have originated as buildings associated with the royal manor to the south of the nearby settlement at Kings Newton. Melbourne Castle was constructed on the site of an earlier manor house of unknown date; there is an old tradition that the manor was originally established in about the year 900, during the reign of Alfred the Great, but there is no evidence for this. As recorded in the Domesday Book, the manor of Melbourne and its lands were the property of King Edward the Confessor prior to the Norman Conquest. The property then passed into the hands of William I of England. After creating the Diocese of Carlisle in 1133, Henry I gave the manor for life to Æthelwold, the first bishop. Some time later, the diocese built a palace nearby on the site of what is now Melbourne Hall. When Bishop Æthelwold died in about 1156, the manor reverted to the crown.A royal hunting park close to Melbourne was probably created by King John around 1200, and the King is known to have stayed at the manor house on at least five occasions. John gave the manor and its lands to Hugh Beauchamp, although they appear to have soon reverted to the crown, being gifted by Henry III to Bishop Walter Mauclerk of Carlisle in about 1230. The estate returned to the crown on the bishop's death in 1248, and Henry granted the land to his son, Edmund Crouchback, 1st Earl of Lancaster, in 1265. At some later date, the manor appears to have been granted to a Philip Marc, before passing to Thomas, 2nd Earl of Lancaster, the King's son. This was in 1298 when he came of age, his father having died two years earlier. Early references to the house itself are rare, but there are records of repairs to the gutters in 1246 and to the roof of the King's Chamber in 1248.

Question: when did the Bishop pass away?
1248