Andronikos Asen was the son of Bulgarian Tsar Ivan Asen III and Irene , who was the sister of Byzantine emperor Andronikos II Palaiologos .
Head entity: andronikos asen Q513490 0 1
Tail entity: irene Q2360993 12
Relation (head \u2192 tail): P25
Inverse relation (tail \u2192 head): P40