|Battle of the Wiar River|
|Part of Russian internal wars during the Middle Ages|
Davyd Igorevich's army
|Kingdom of Hungary|
|Commanders and leaders|
|King Coloman of Hungary|
|Casualties and losses|
The Battle of the Wiar River (Russian: Битва на Вагре) is a battle that took place in 1099 between the warriors of Davyd Igorevich, Prince of Dorogobuzh and the Cuman army led by Khan Bonyak , on the one hand, and the troops of king Coloman of Hungary, on the other, on the river, which is named in the annals of Vagra (Ukrainian: Vіhor, Viar|, Polish: Wiar). The battle ended in total defeat of the Hungarians and the distruction of the Hungarian army.
After the blinding of Vasilko Rostislavich of Terebovl by Davyd Igorevich, Svyatopolk II Izyaslavich, seized Vladimir and decided to attach the south-western Russian lands, where the Rostislavichi reigned, but was defeated by them in the battle of Rozhne Pole.
Svyatopolk II Izyaslavich sent his son Yaroslav for help against Volodar Rostislavich of Peremyshl  by the King Coloman of Hungary, who decided to use the situation to strengthen its position in the Carpathian Ruthenia . Volodar took up defensive positions in Peremyshl, and Davyd led troops to the aid of the Cuman Khan Bonyak.
The Hungarians who outnumbered their enemy, lined up for battle in a narrow mountain valley. Bonyak divided his few soldiers into two groups. Davyd's squad of one hundred people remained standing on the field of battle, while half a hundred horsemen led by the Cuman Khan Altunopa were sent by Bonyak ahead to pretend they retreated and lure the Hungarians into a trap. Firing Hungarians, Kuman Altunopa turned back, dragging those behind him. When Hungarians came to the ambush, Bonyak suddenly hit them in the rear and turned a demoralized enemy to flight. Then the soldiers of Altunopa and Bonyak brought the Hungarians down in a heap on the edge of a rocky cliff, where the environment is due to tightness pushed each other into the abyss. More Hungarians were killed in the pursuit, many of them drowned in the Wiar and San rivers.
The Rostislavichi brothers defended their possessions in the Carpathian region. Davyd took advantage of the defeat of the enemy, capturing Vladimir and Lutsk , but not for long. Volhynia became again a vassal of Kiev, and Davyd received the Principality of Dorogobuzh .