Antiochus I Theos Dikaios Epiphanes Philorhomaios Philhellen (r. c. 69-34 BCE) was the most celebrated king of Commagene and the founder of its Greco-Iranian dynastic ruler cult. Son of Mithridates I Kallinikos and the Seleucid princess Laodice Thea Philadelphos, he advertised a double descent from the Achaemenid line of Darius the Great on his father's side and from Alexander's Macedonian Seleucid successors on his mother's. On the summit of Mount Nemrud he raised a 50-metre funerary tumulus flanked by terraces of colossal enthroned statues, and in the great cult law (the nomos) he consecrated his own deified image among the gods, decreeing perpetual monthly rites. He is the human figure of the dexiosis reliefs, shown grasping the right hand of each god in turn to proclaim his reception into divine company; the accompanying Lion Horoscope, the earliest dated Greek horoscope, fixed the auspicious astral moment of his cult. Though raised to the gods as Theos, he is consistently presented as joining and serving the ancestral divine assembly rather than supplanting its supreme head.