Wiki information Chryselios:

John Chryselios
Man, Person

John Chryselios was a Byzantine provincial magnate in late 10th-century Dyrrhachium, and the father-in-law of Tsar Samuel of Bulgaria.

Noble person, Person

Kosara or Cossara was Empress of Bulgaria as the wife of Emperor Samuel, whom she married in about 970 AD. Her father was John Chryselios from Dyrrhachium. Her name and religion suggest that she was a Paulician from Armenia.