Turning his sights on the Seleucid realm, Mithridates I invaded Media and occupied Ecbatana in 148 or 147 BCE; the region had recently become unstable after the Seleucids suppressed a rebellion led by Timarchus. Mithridates I afterwards appointed his brother Bagasis as the governor of the area. This victory was followed by the Parthian conquest of Media Atropatene. In 141 BCE, Mithridates I captured Babylonia in Mesopotamia, where he had coins minted at Seleucia and held an official investiture ceremony. There Mithridates I appears to have introduced a parade of the New Year festival in Babylon, by which a statue of the ancient Mesopotamian god Marduk was led along parade way from the Esagila temple by holding the hands of the goddess Ishtar. With Mesopotamia now in Parthian hands, the administrative focus of the empire relocated towards there instead of eastern Iran. Mithridates I shortly afterwards retired to Hyrcania, whilst his forces subdued the kingdoms of Elymais and Characene and occupied Susa. By this time, Parthian authority extended as far east as the Indus River.