Sisak (Armenian: Սիսակ) was the legendary ancestor of the Armenian princely house of Syuni, also called Siunids, Syunid and Syuni.[1] The Armenian historian Movses Khorenatsi states that Sisak was the brother of Harmar who was known as Arma, son of Gegham and a descendant of the legendary patriarch of the Armenians, Hayk.[2] Gegham had taken up residence near Lake Sevan and, following his death, the lands encompassing the areas from Lake Sevan to the Araks River were inherited by Sisak.[1] The region assumed Sisak's name (Armenian: Սիսական; Sisakan) after he died,[1] and those who descended from his dynastic line were known in Armenian as Syunis (in Armenian, Սյունիներ; Syuniner) or Sisakyaner (Սիսակյաններ). After the Kingdom of Armenia introduced the system of administrative divisions known as nahangs (provinces) in the 2nd century BC, the Siunis were confirmed by King Vagharshak I the Parthian as the lords of the province of Syunik.[3]
Historian Robert H. Hewsen contends that:
Sisak...can only be another eponym, and a late one at that. Sisak is said to have been the ancestor of the princes of Siwnik', a province on the southern border of Geghak’uni. It was called Sisakan by the Sasanids (who ruled Persia from 226 to 637 A.D.); this term was unknown to Armenian historiography before the seventh century A.D. and was first used by a Syrian writer only in the sixth century.[4]