Sir William Montacute, 2nd Baron, eldest son of Sir Simon, served in several expeditions into Scotland, and distinguished himself, and as a reward for his services was made Knight of the Bath. In the reign of Edward I, he received the honour of Knighthood, along with Edward, Prince of Wales; and in the 2nd year of Edward II, he obtained the royal charter for free warren at his Manor of Aston Clinton in County Bucks, as he did afterwards for those of Saxlington in Norfolk, Knolle in Somerset, and Waneford in Devon. In the same reign he was Governor of Berhamstead Castle and Steward of the king's household; and had a grant of the bodies and ransom of Rene ap Grenon and Madoc ap Vaughan, and Andeon ap Madoc, Welsh Barons who had rebelled and been taken prisoners. Moreover, he obtained from the king a special license to make a Castle of his house at Kersington in Oxford, and was appointed Seneschal of the Duchy of Aquitiane in France, and at last of Gascony in 1318. In 1318-1319 he had summons to Parliament, and died 1320 in Gascony, but was interred at St. Frideswide, now Christ Church, Oxen. By Elizabeth, daughter of Peter, Lord Montford of Beaudefort, in County Warrick, he had issue 4 sons and 7 daughters.