A licence to refortify the castle. Not, in a meaningful sense, a licence to crenellate although has been called this by some.

Mandeville, William de, third earl of Essex (d. 1189), magnate and courtier, was the second son of Geoffrey de Mandeville. Earl William became a regular member of Henry II's entourage shortly after his investiture. His rise at court was due as much to his own considerable military and diplomatic skills as to the deaths of the king's earlier baronial advisers. And the bond of friendship that existed between the earl and king from the first never diminished. Throughout the 1170s and 1180s the earl was either at Henry's side, or engaged in royal business elsewhere. It is possible to trace his movements back and forth from England and the continent in the pipe rolls. Between 1173 and 1187 no fewer than nineteen channel crossings are recorded, some of them relating to embassies led by Mandeville to the courts of Flanders, France, and Germany. The high respect with which Mandeville was regarded by the Angevin court is illustrated by a passage from the Histoire de Guillaume le Maréchal (1271–5). When in 1188 Philip Augustus of France suggested that he and Henry II should settle their differences through a trial by combat, William Marshal volunteered that the English champions should be himself and William de Mandeville. There were many rewards for royal service. Over a twenty-two-year period, the minuscule sum of £174 was levied by the English exchequer against Mandeville in the form of scutages, aids, forest pleas, murder fines, and communal taxes. Of this amount, the sum of £3 was all that was ever paid into the exchequer, the remainder being pardoned. In contrast, Mandeville took more than £1600 from the exchequer in terrae datae, outright gifts, and the third penny of Essex. An even more valuable reward came to him through his marriage in 1180, arranged by Henry II, to Hawisa (d. 1213/14), heir to the Anglo-Norman lands and fees of the counts of Aumale. (Keefe)