Heraclius spent the rest of winter to the north of Lake Van. In 625, his forces attempted to push back towards the Euphrates. In a mere seven days, he bypassed Mount Ararat and the 200 miles along the Arsanias River to capture Amida and Martyropolis, important fortresses on the upper Tigris. Heraclius then carried on towards the Euphrates, pursued by Shahrbaraz. According to Arab sources, he was stopped at the Satidama or Batman Su River and defeated; Byzantine sources, however, do not mention this incident. Another minor skirmish between Heraclius and Shahrbaraz took place at the Sarus river near Adana. Shahrbaraz stationed his forces across the river from the Byzantines. A bridge spanned the river, and the Byzantines immediately charged across. Shahrbaraz feigned retreat to lead the Byzantines into an ambush, and the vanguard of Heraclius' army was destroyed within minutes. The Sasanians, however, had neglected to cover the bridge, and Heraclius charged across with the rearguard, unafraid of the arrows that the Sasanians fired, turning the tide of battle against the Sasanians. Shahrbaraz expressed his admiration at Heraclius to a renegade Greek: "See your Emperor! He fears these arrows and spears no more than would an anvil!" The Battle of Sarus was a successful retreat for the Byzantines that panegyrists magnified. In the aftermath of the battle, the Byzantine army wintered at Trebizond.