William Longsword


William Longsword was the son of Rollo, in the 930s he emerged from obscurity because of his war with Arnulf of Flanders, and  his support for King Louis IV (d’Outremer). In December 942 Arnulf called for a peace conference with William; there, William was murdered.
Arnulf is said to have arranged the assassination
Assassination of William Longsword

(BNF, FR 2813) Grandes Chroniques de France
14th Century