Beof, Bois, Bos, Booz
He accompanied Arthur on the Roman campaign, and was one of the three messengers that Arthur sent to meet with the Roman Procurator Lucius - an effort that resulted in ruin when Gawaine killed a Roman warrior.
In the ensuing battle, Boso managed to capture the Roman leader Petreius Cotta (or Peredur).
He also led a company of soldiers at the final battle at Soissons. His role is taken by Bors in Malory.