The Cambridge History of India, Vol. I: Ancient India v1.c31.32

v1.c31.32

In eastern Irān the 'King of Kings' and the prince of his family who was associated with him in the government issued coins bearing the names of both—the former in Greek on the obverse, and the latter in Kharoshṭhī on the reverse. Greek was the ordinary language of coins throughout the Parthian empire: it was not characteristic of any particular province. Kharoshṭhī, on the other hand, was, in eastern Irān, restricted to Arachosia (Kandahār). We may reasonably infer therefore from his Kharoshṭhī coin-legends that the viceroy governed this province in the upper valley of the Helmand and its tributaries. The other province, Drangiana (Seistān), was most probably under the direct rule of the suzerain.