and a calathus) and is depicted in front of the king. Some scholars have seen Alexander as little more than a Ptolemaic puppet, arguing that this coinage emphasises Cleopatra's dominance over him and that the chancellor Ammonius was a Ptolemaic agent. Other scholars argue that the alliance was advertised as an important one, but that the arguments for Alexander's subservience have been overstated. Collapse of the East Meanwhile, the Seleucid positions in the eastern Upper Satrapies, already weakened by the previous kings' failure to contain the Parthians and the Greco-Bactrians, suffered almost complete collapse. The Parthians under Mithridates I took advantage of the general instability to invade Media. The region had been lost to Seleucid control by the middle of 148 BC. At around the same time the local nobles in Elymais and Persis asserted their own ephemeral independence, only to be soon also subdued by the Parthians. By 148 BC at the latest the Parthians also secured their hold over Hyrcania at the coast of the Caspian Sea. By 147 BC the Parthians stood at the doorsteps of Babylonia, one of the Seleucid empire's hearthlands and location of one of its two capital cities, Seleucia-on-Tigris. Alexander is not recorded to do anything of note to stem the steady erosion of Seleucid power in the East. Ancient historians hostile to him depict him as too distracted by a life of debauchery to take action to stop the Parthians, unlike earlier Seleucid Kings who would mount expeditions to the eastern satrapies to deter the Parthians. He was reputed to hand the administration over to two commanders, Hierax and Diodotus, neither of whom seemed to care for anything but their own interests. This representation is at least partially a product of his opponents' propaganda, but it is true that under Alexander, the Seleucid Empire continued to see its reach and power slip away. War with Demetrius II and death (147–145 BC) In early 147 BC Demetrius' son Demetrius II returned to Syria with a force of Cretan mercenaries led by a man called Lasthenes. Much of Coele Syria was lost to him immediately, possibly as a result of the succession of the regional commander. Jonathan attacked Demetrius's position from the south, seizing Jaffa and Ashdod, while Alexander Balas was occupied with a revolt in Cilicia. In 145 BC Ptolemy VI of Egypt invaded Syria, ostensibly in support of Alexander Balas. In practice,