Ivan Asen II of Bulgaria
Beloslava was the daughter of tsar Ivan Asen II of Bulgaria and his first wife Anna (religious name Anisia), mentioned in the Synodik of the Bulgarian Church. The couple had another daughter - Maria, who married Manuel of Epirus. It is possible that Beloslava and her sister Maria were illegitimate children of Ivan Asen because his first marriage with Anna was not recognized by the Bulgarian Orthodox Church. But there was no dоubt about the noble birth of his daughters, so both were married to men of high aristocratic status.