Ariarathes IV of Cappadocia

Ariarathes IV, surnamed Eusebes, "the Pious", (Ancient Greek: Ἀριαράθης Εὐσεβής, Ariaráthēs Eusebḗs), was the king of Cappadocia in 220–163 BC.

[2] He married his cousin Antiochis, the daughter of Antiochus III the Great, king of Syria, and Laodice III, and, in consequence of this alliance, assisted Antiochus in his war against the Romans.

After the defeat of Antiochus by the Romans in 190 BC, Ariarathes sued for peace in 188, which he obtained on favourable terms, as his daughter, Stratonice, was about that time betrothed to Eumenes II, king of Pergamum, whom she later married, and became an ally of the Romans.

In 183–179 , he assisted Eumenes in his war against Pharnaces, king of Pontus.

Polybius mentions that a Roman embassy was sent to Ariarathes after the death of the Seleucid Antiochus IV Epiphanes, who died 164.