A Swiss or German Baselard. 13 ½” overall, 9 ½” triangular blade with shallow medial ridge and broad converging fullers at the forte, I-shaped hilt with replacement bone grips fixed with rivets and with a repeated quatrefoil pattern of inlaid pellets.
15th century (grip later)
Examples of this age are exceedingly rare, this one is in good condition and restored with a bone grip by Chris Dobson - formerly Master Armourer to the Royal Armouries.
See ‘Antique Edged Weapons’ by Southwick page 195