This is part of a family of 'cuff' hilted swords common across the Byzantine empire and areas of its influence. The style actually dates back to Samanid period. In later times it can be observed as recently as the 18th century in Omani swords. It was used across a very large area and turns up in everything from medieval Mamluk weapons to early Islamic swords in Syria and Arabia.
Yours conforms broadly to others published in the works by Yotov available online regarding finds in Bulgaria and southern Europe.
I would roughly place this in the 10th to 12th centuries.
The guard looks like it might be on backwards by the way.
I had the pleasure to do a short article on another similar sword from Dr. Lee Jones which you can find here:
http://iainnorman.com/articles-2/25