A RARE ceremonial knife, possibly 17th century, having a brass handle featuring a King holding his orb and sceptre

The age and purpose of this knife is unknown to me. It measures 11 1/2" long and has a beautifully engraved steel blade with a latin inscription near the tip. One side of the blade is engraved with sheet music and the other side features hounds chasing a stag. Along the borders of the blade are stylized human creatures in various positions. In my opinion the blade appears to 16th or 17th century. The heavy solid brass handle features a northern European king with a crown and having a beard. Fabulous detail work.