At the beginning of 1295, Latimer was in command at Rions and seems to have remained in Gascony till 1297, after which he was employed in Scotland, and was present at the Battle of Stirling Bridge on 10 September 1297, when the English were defeated by William Wallace.
The following year, in April, he was appointed a commissioner to treat for the exchange of prisoners, and was one of those summoned to attend the council at York in July for the consideration of the affairs of Scotland.
William was at the siege of Caerlaverock, appointed in October 1300 again as keeper of Berwick and in September 1302 was in command at Roxburgh Castle.
William married Alice, elder daughter and co-heiress of Walter Ledet, Lord of Braybrooke and Ermentrude de Lisle.
The wardship of Alice and her sister Christiana was held by the father of William Latimer, who married them to his sons.