He was at the Battle of Falkirk in 1298 and at the Siege of Caerlaverock Castle in Scotland in 1300, with the king. He signed and sealed the Barons' Letter of 1301 to the pope as "Walt(er)us de Bello Campo, D(omi)n(u)s de Alcestre" ("Walter de Beauchamp, Lord of Alcester"). Another of the signatories was his nephew Guy de Beauchamp, 10th Earl of Warwick (c.1272-1315).