Four Point Crown Half Buckle 1250-1400AD
It features a decorative pattern similar to a crown along the edge. Solid brass it is both strong and stylish. A similar buckle from England was dated to 1250-1400 A.D. and can be seen here:
https://finds.org.uk/database/artefacts/record/id/1131115
https://finds.org.uk/database/artefacts/record/id/1110491