|1211||Battle of the Rhyndacus||★ ★ ★ ★ ★|
|Outcome:||A victory of the Latins who secured northwest Anatolia||15 October 1211|
|War & Enemy:||
|The Battlefield|| Location:
Rhyndacus river, modern Mustafakemalpasha River or Orhaneli River n northwestern Anatolia in the Bursa Province of Turkey
| Modern Country:
|The Byzantines(emperor: Theodore I Laskaris)||The Enemies|
|Commander:||Emperor Theodore I Laskaris||Emperor Henry of Flanders|
|Background story:||The Latin emperor of Constantinople Henry of Flanders, desired to expand his territory in Asia Minor at the expense of the Nicaeans. He had already achieved a victory in 1205 at Adramyttium, but the need to counter the Bulgarians in Europe had forced him to conclude a truce and abandon Asia Minor. By 1211, only a small exclave around Pegae remained in Latin hands.
Taking advantage of the losses suffered by the Nicaean army against the Seljuks in the Battle of Antioch on the Meander, Henry landed with his army at Pegae and marched eastward to the Rhyndacus river. Henry had probably some 260 Frankish knights, while Laskaris had a larger force overall, but only a handful of Franks (Latin mercenaries), who had suffered especially heavily against the Seljuks.
Laskaris prepared an ambush at the Rhyndacus, but Henry assaulted his positions and scattered the Nicaean troops in a day-long battle on 15 October. The Latin victory, won without casualties, was crushing: after the battle Henry marched unopposed through Nicaean lands, reaching south as far as Nympheon.
|Aftermath:||The Byzantines signed the Treaty of Nymphaeum, which gave the Latin Empire control of most of Mysia up to the village of Kalamos (mod. Gelembe), which mark the boundary between the two states.|