Sir William Grandison and Henri de Bouvillars
Sir William de Grandison Warden of the Isles 1294
William was Otto's younger brother and was in the service of Edmund, Earl of Lancaster. On 4 November 1288 he had letters of protection when remaining in Wales in order to fortify the castle of Carnarvon, and was still there on 6 November 1289, taking the place of Otto. On 3 May 1292 he had licence to strengthen his house of Ashperton with a wall of stone and lime and to crenellate it. He was excepted from military service in Gascony in 1294, in which year he appears as Warden of Jersey and Guernsey for his brother.
He was summoned to Carlisle for military service on 26 September 1298. He was summoned to Parliament from 6 February 1299 to 10 October 1325, by writs directed Willelmo de Grandisono, whereby he is held to have become Lord Grandison; and was present at a meeting of Parliament on 5 April 1305 at the Westminster house of his brother, Otes de Grandison, shown as Archbishop of York.
He was summoned again for military service and to various Councils from 7 May 1299 to 21 March 1333. He was in Gascony with Edmund, Earl of Lancaster, before 1 January 1296, when his lands were restored to him, seized by the Crown on an order to take all lands of alien laymen of the power of France, but William de Grandison was still in the King's faith. He was present at the siege of Carlaverock in July 1300. He was summoned to the Coronation of Edward II on 18 January 1308. On 23 February 1310 he had letters of protection on going beyond the seas.
Complaint of assault
In 1318 the Prior of the Hospital of St John of Jerusalem complained that William de Grandison and Piers, his son, and Otes, brother of Piers, and others had broken into his houses at Dartford in Kent and robbed and assaulted, to which accusation there was a counterclaim by William de Grandison that there had been theft of his goods there. Having been summoned for military service in 1322, he did not attend the muster, and his lands were seized; but the absence being due to severe illness, licence was given him to remain at home for the more speedy restoration of his health, provided that he sent at least six men-at-arms for the expedition.
Letters of protection
He had letters of protection going to Ireland on 16 June 1327, and on 20 September 1329 had respite of homage till Easter following, as the King had learnt that he was so infirm and aged that he was unable to come. He was, however, summoned on 12 July 1332, to be with the King at Michaelmas and take passage to Ireland on the expedition there.
He married, in or before 1285, Sibyl, younger daughter and coheir of Sir John Tregoz, by his first wife, Mabel, daughter of Sir Fulk Fitzwarin. On 26 November 1300 it was ordered that the lands of Sir John Tregoz should be divided between William de Grandison and his wife and the other coheir, they having done homage. His wife died 21 October 1334, and was buried at Dore Abbey. He died 27 June 1335, and was presumably also buried at Dore Abbey.