He was son of Odo (Eudes) de Beaumont, viscount of Chaumont-en-Vexin.
He took a part at the First Crusade as part of the army of Hugh the Great that attempted to capture the Holy Lands, called by Pope Urban II in 1095.
Walo was killed by the Turks during the Siege of Antioch on 20 May 1098.
[2] Walo and Humberge had three children: Drogo was the ancestor of the later counts of Dammartin, his great-grandson Jean, Châtelain de Trie, marrying Alix de Dammartin, daughter of Alberic III, Count of Dammartin.
Riley-Smith, Jonathan, The First Crusaders, 1095–1131, Cambridge University Press, 1997