Battle of Hyelion and Leimocheir The Battle of Hyelion and Leimocheir saw the almost complete destruction by the Byzantines , in an ambush at a river crossing , of a large Seljuq Turk army which had been raiding the Maeander Valley in Anatolia and had sacked a number of Byzantine cities . Background . Following Emperor Manuel Komnenos ' s defeat at the Battle of Myriokephalon ( 1176 ) the Byzantines failed to implement all the conditions , particularly the destruction of border fortresses , demanded by the Seljuq sultan Kilij Arslan II as a prerequisite for a cessation of hostilities . A substantial Seljuq cavalry army , including Turcoman nomad auxiliaries , was dispatched into Byzantine territory , in the Meander Valley in western Anatolia , on a retaliatory raid . A Byzantine army under the general John Komnenos Vatatzes , the emperor ' s nephew , set out from Constantinople with instructions to intercept the Seljuq raiders . Vatatzes was given two other generals as his subordinates , Constantine Doukas and Michael Aspietes , and was able to pick up reinforcements as his army moved through Byzantine territory . Battle . The date of the battle is unknown , it has generally been ascribed to the year 1177 on the basis of its position within the narrative of Niketas Choniates . The Turks , who had orders to ravage the Meander Valley as far as the sea - shore , sacked the Byzantine settlements of Tralles , Antioch , Louma and Pantacheir . As a result of these successes , they were loaded with plunder , including , rather poetically , water from the sea , an oar and shore sand . These burdens would have drastically slowed their progress and lessened their tactical mobility . The Seljuq army was returning towards Turkish territory when it approached a " choke point " in its journey where the great eastern highway crossed the Meander River by way of a bridge ( probably ruined or semi - derelict ) , near the villages , or forts , of Hyelion and Leimocheir . The Byzantines had concealed themselves and were divided into two corps , separated by the river . They caught the Seljuq army in an ambush when it had partially crossed over the river , destroying it as a fighting force . The Byzantine light troops played a prominent role in the battle ; posted on high ground they are described as raining missiles down onto the near helpless Seljuqs . Many of the Seljuq soldiers tumbled into the river and were drowned . The Seljuq commander , known as " Atapakos " in Greek sources — evidently a bearer of the title of " Atabeg " — tried to help his forces cross the river by rallying the most heavily armed of his cavalry and attacking the Byzantines . This attack having failed , he tried to save himself by swimming across the river with his horse . When he reached the opposite shore , however , he was killed by an Alan soldier of the Byzantine force . Following the death of their commander the Seljuq troops fled in disorder , with a great number of them being drowned in the river ; Choniates stating that only a few out of many thousands were able to save themselves . On the Byzantine side , the general Michael Aspietes fell ; he was drowned in the Meander when thrown by his wounded horse . Aftermath . The battle was a significant Byzantine victory and it underlined how limited the immediate effects of the Byzantine defeat at Myriokephalon were on the empire ' s hold over its Anatolian possessions . The Byzantine victory was followed up by punitive expeditions against the Turcoman nomads settled around the upper Meander Valley . It is interesting to note that the Byzantine strategy at this battle , ambushing a raiding army on its return journey when it would be slowed by plunder and captives , is exactly what is prescribed in much earlier Byzantine military treatises , such as the " Tactica " of Leo VI ( 886 – 912 ) . This points to a retention by Byzantine commanders of knowledge of the successful military strategies of the past . The emperor Manuel died in 1180 ; his son and successor Alexios II Komnenos was a minor , and the empire was governed by a divided regency . Without the strong presence of Manuel , the military advantage in Anatolia reverted to the Seljuqs . Sultan Kilij Arslan invaded the empire in 1182 , when Byzantium was distracted by the coup d ' état of Alexios ' s cousin Andronikos Komnenos , and following the Siege of Cotyaeum captured the towns of Sozopolis and Cotyaeum .