1. Historical framework
After the defeat by the Arabs in the summer of 782 in Bithynia, the empress Eirene Athenaia was forced, at the same year, to sign a treaty with humiliating terms for the empire.1 According to them, Byzantium was obliged to pay to the Arabs 90.000 gold pieces every April and 70.000 every June. In return, the latters were bound not to undertake their “established” annual invasions in the Byzantine territories of Asia Minor.
The peace lasted for three years. In 785 the empress decided to stop the payments towards the Arabs. The reasons behind this decision were probably her conviction that the treaty was not necessary any more and her desire to get rid of its humiliating terms before proceeding to a clash with the iconoclasts.2 The result of this action was the reprisal of the annual Arab invasions to the borderline regions. During the summer of the same year, the Arabs invaded the theme of Armeniakon, whereas in 786 the Byzantines destroyed the frontier castle of Adata that the Arabs had abandoned.
The new Harūn ar-Rashīd did not show in the early years of his reign a great interest in continuing the hostilities against the Byzantine lands of Asia Minor, and the first invasions that he organized were of a small scale. However, during the summer of 788, a strong enough Arab expeditionary corps invaded through the Cilician Gates against the frontier regions of the theme of Anatolikon.3 Military forces from the themes of Anatolikon and of Opsikion hastened to withhold the invaders and, on September 788, they clashed together in the battle at Podandos, near the Cilician Gates.
2. The battle
The place where the battle took place is referred to in the sources as Kopidnadon. This name is not attested from other sources and the most likely identification is with the city of Podandos in Cappadocia; Podandos was actually a town near the western exit of the passage of the Cilician Gates.4 It seems, thus, that the reaction of the Byzantines was immediate.
The battle ended with the victory of the Arabs. The Byzantines suffered heavy losses in both soldiers and officials of the themes. These thematic force comprised also soldiers from the , who had enlisted voluntarily in these themes, after Eirene had fired them from the tagmata in 786. The most important loss for the Byzantines was, according to the sources, the death of Diogenes, of a capable and brave of the theme of Anatolikon.
The immediate consequences of the battle at Podandos and of the defeat of the Byzantines by the Arabs were not important. From the sources we can deduct that the losses of the Byzantines were great, but not dramatic. We do not have any information about extensive plundering of the region from the side of the Arabs, maybe because of the immediate reaction of the Byzantine troops. It seems, thus, that it was yet another annual invasion of the Arabs, without any particular consequences for the populations and the lands of the region.
A more important consequence of the battle and of the defeat of the Byzantines was, judging from the sources, the death of the tourmarch Diogenes. The loss of a brave and capable officer must have weakened the army of the Anatolikon and bent the moral of the soldiers. Iterestigly, according to some scholars, there was also a collateral effect of this loss: the birth of the legend of Digenes Akritas, who had as its historical core and substratum the facts of the battle on September 788 and the death of the tourmarch Diogenes.5