Wow, we don't have much to go on with this one! I know that 6-sided blades such as this were very popular with Spanish swords of the 17th-early 19th century. Curiously, although fitted for Spanish swords, most of the blades at that time were made in Germany for export. If we assume it is made for the Spanish market and of the time period mentioned, this blade would have been made most likely for a Spanish bilbo pattern cavalry sword or possibly a dish/cup hilt broadsword. The markings tell us little, as the sun and moon symbols are used throughout Europe. This is just my opinion and I'll open the floor for others now!
