The article substantiates the view that the founder of the Mamikonyan clan moved to Armenia at the end of the 3rd century. His great-grandson, Artavazd II had three wives. Almost all the children of Artavazd II died in the tumultuous events in Armenia and Iran in the second third of the 4th century. The Mamikonyans later went back to Artashen, the youngest son of Artavazd II by his second wife.