The consequence of this victory, achieved in the name of Gallus, was, that the army renounced allegiance to the betrayer of Decius and chose their general as his successor. Once more therefore civil war took precedence of frontier-defence; and, while Aemilianus no doubt vanquished Gallus in Italy but soon afterwards succumbed to his general Valerianus (254), Dacia was lost for the empire--how, and to whom, we know not.[140] The last coin struck by this province, and the latest inscription found there, are of the year 255, the last coin of the neighbouring Viminacium in upper Moesia of the following year; in the first years of Valerianus and Gallienus therefore the barbarians occupied the Roman territory on the left bank of the Danube, and certainly also pressed across to the right. Before we pursue further the development of affairs on the lower Danube, it appears necessary to cast a glance at piracy, as it was then in vogue in the eastern half of the Mediterranean, and the maritime expeditions of the Goths and their allies originating from it. [Sidenote: Piracy on the Black Sea.] That the Roman fleet could at no time be dispensed with on the Black Sea, and piracy there was probably never extirpated, was implied in the very nature of the Roman rule as it had taken shape on its coasts. The Romans were in firm possession only from about the mouths of the Danube as far as Trapezus. It is true that on the one hand Tyra at the mouth of the Dniester and Olbia on the bay at the mouth of the Dnieper, on the other side the Caucasian harbours in the regions of the modern Suchum-Kaleh, Dioscurias and Pityus, were Roman. The intervening Bosporan kingdom in the Crimea also stood under Roman protection, and had a Roman garrison subject to the governor of Moesia. But on these shores, for the most part far from inviting, there were only those posts formerly held either as old Greek settlements or as Roman fortresses; the coast itself was desolate or in the hands of the natives filling the interior, who, comprehended under the general name of Scythians, mostly of Sarmatian descent, never were, or were to become, subject to the Romans; it was enough if they did not directly lay hands on the Romans or their clients. Accordingly, it is not to be wondered at, that even in the time of Tiberius the pirates of the east coast not merely made the Black Sea insecure, but also landed and levied contributions on the villages and towns of the coast. If, under Pius or Marcus, a band of the Costoboci dwelling on the north-western shore fell upon the inland town Elateia situated in the heart of Phocis, and came to blows under its walls with the citizens, this event, which certainly only by accident stands forth for us as isolated, shows that the same phenomena which preceded the downfall of the government of the senate were now renewed, and even with the imperial power maintaining itself outwardly unshaken not