If Hecatomnus did not become satrap immediately upon the death of Tissaphernes, he was in office by 392 BCE, when he made war on Evagoras of Salamis on the orders of Artaxerxes. Hecatomnus therefore became satrap of Caria  BCE.
Hecatomnus did not immediately become satrap upon Tissaphernes' death but was in office by 392 BCE when he fought against Evagoras of Salamis at Artaxerxes' behest. Thus, Hecatomnus became the satrap of Caria around 392 BCE.