Wikipedia
The Malakasioi were a Vlach tribe or clan that moved from central Albania into Greece in the 14th century,
The Byzantine emperor and historian, John Kantakouzenos, who reports their arrival, called them "Albanians", as they most likely came from the plain of Malakastra between Valona and Berat (in central Albania), but they were Vlachs. They came south along with the tribes of the Bouioi and Mesaritai in the 14th century, and settled "in no town but in inaccessible places" in the central Pindus Mountains, between Thessaly and Epirus. According to Alain Ducellier they left due to social oppression and upheavals.
From 1367 to 1370, Ioannina, the capital of Thomas Preljubović, was under constant siege and blocked by the Mazaraki and Malakasioi clans under Peter Losha. In 1411, Stephen Bouisavos, the leader of the clan, submitted to Carlo I Tocco, the new lord of Ioannina, and was named protostrator.