Elena (Bulgarian: Елена) was the second wife of tsar Ivan Asen I of Bulgaria.
She is sometimes alleged to be a daughter of Stefan Nemanja of Serbia, but this relationship is questionable and would have caused various canonical impediments to marriages between their descendants.
In 1188, Elena was captured by enemy Byzantine forces during their attempted Siege of Lovech and kept in Constantinople as a hostage by Emperor Isaac II Angelos.
[1][2] When Ivan Asen ascended the throne as co-tsar, he sent his younger brother Kaloyan to Constantinople as hostage in exchange for Elena.
Her memory is honored in the Synodic of Bulgarian Church:[3] For Elena, the new and pious tsarina, mother of the great tsar Ivan Asen, adopted then an angelic image and called Evgenia, may her memory live forever.After her son ascended the throne, Elena was honored as empress dowager.