Tarkumuwa was the issuer of coins in Cilicia in succession to Pharnabazus from the 370s BC, possibly as satrap of the region.
He is often been identified with Datames, the satrap of Cappadocia. Wikipedia conflates the two men. For discussion see
Casabonne O. 'De Tarse à Mazaka et de Tarkumuwa à Datamès: d'une Cilicie à l'autre?' in: La Cilicie : espaces et pouvoirs
locaux (IIe millénaire av. J.-C. – IVe siècle ap. J.-C.). Actes de la Table Ronde d’Istanbul, 2-5 novembre 1999. Istanbul
: Institut Français d'Études Anatoliennes-Georges Dumézil, 2001. pp. 243-263. (Varia Anatolica, 13); https://www.persee.fr/doc/anatv_1013-9559_2001_act_13_1_988