The Galatian leader Domnilaus was the tetrarch of the tribe of the Tectosagi. He is probably identified with the Galatian tetrarch Domneclius, father of Adiatorix, who was the high priest of the sanctuary at Pessinus.1 His brother was probably Castor I Tarcondarius, also a tetrarch of the Tectosagi. If the two tetrarchs were indeed brothers, then they might have been the sons of the Galatian leader to whom Pompeius ceded the tetrarchy of the Tectosagi during the administrative organization of Asia Minor in 63 BC. Domnilaus must have shared with Castor the leadership of the tetrarchy, according, however, to a more plausible version, the two leaders governed separate parts of the area of the Tectosagi. In this case the dominion of Domnilaus was at the northern part of the tetrarchy, as inferred by the fact that Castor I most certainly lived in the south.2
When the second civil war broke out in Rome (49-45 BC), Domnilaus, like the other Galatian tetrarchs of the region, took the side of Pompeius. In the battle which took place at Pharsalus in Thessaly in 49-48 BC, he participated with a cavalry unit of 300 men, led by Castor II, son of Castor I Tarcondarius. Since this is the only historical reference to Domnilaus, it is concluded that the Galatian was killed in action. After his death apparently his dominion was taken over by the king of the Tolistobogii Deiotarus I and his son, Deiotarus II, as inferred by the fact that the tomb of Deiotarus II was found near the Galatian fort of Bloukion, in an area where most probably the northern section of the tribe of the Tectosagi had settled.
Child(ren):