Antiochus claims in his inscription on Mount Nemrut that he was a friend of the Romans (philoromaios), but was seen with some mistrust by a few of the informants of Roman politician Cicero. His Iranian lineage made him lean toward the Parthian realm. He enjoyed good relations with the king of Media Atropatene, Darius, who seemingly helped him against Pompey. Antiochus made an alliance with the Parthian monarch Orodes II (r. 57 - 37 BC), which was cemented with Orodes' marriage to Antiochus' daughter, Laodice. However, in 51 BC Antiochus provided Cicero with intelligence of the movements of a Parthian force led by prince Pacorus I. Ultimately Antiochus chose the Parthians over the Romans. In 38 BC, Pacorus was defeated and killed by the Romans; the remnants of his army fled to Commagene, where they took refuge.