The death of Seleucus IV in 175 BC and the presence of Demetrius I in Rome led to the young Antiochus proclamation as king,[3] but the minister Heliodorus who probably killed Seleucus IV held the real power.[1] Antiochus IV soon arrived in Syria and proclaimed himself a co-ruler, in a succession that was illegal.[3] Antiochus IV disposed of Heliodorus and kept his nephew in the shadow.[4] The young Antiochus died in 170/169 BC (145 SE (Seleucid year)), possibly on the orders of Antiochus IV.[note 1][6]