[size=14pt]Battle on the Marchfeld[/size]
Czech king Ottokar II of Bohemia lost against German king Rudolph I of Habsburg.
The Battle on the Marchfeld (i.e. Morava Field; Czech: Bitva na Moravském poli) at Dürnkrut and Jedenspeigen took place on 26 August 1278 and was a decisive event for the history of Central Europe for the following centuries. The opponents were a Bohemian (Czech) army led by the Přemyslid king Ottokar II of Bohemia and the Imperial army under the German king Rudolph I of Habsburg in alliance with King Ladislaus IV of Hungary. Although both sides had in their units also infantry, the battle itself was primarily a great collision of heavy knights cavalry, though the Cuman horse archers in the Hungarian army played a vital role. The battle was finally won by an ambush attack of the united Imperial-Hungarian forces, which was in those times considered dishonourable and against the rules of knighthood.
[pre][/pre]After three hours of continued fighting on a hot summer day, Ottokar's knights in their heavy armour were exhausted, many of them suffered from circulatory failure and were not able to move. At noon Rudolph ordered a fresh heavy cavalry regiment he had concealed behind nearby hills and woods to attack the right flank of Ottokar's troops. Such ambushes were indeed commonly regarded as dishonourable in warfare and Rudolph's commander Ulrich von Kapellen apologized to his own men in advance. Nevertheless the attack prevailed in splitting and stampeding the Bohemian troops. Ottokar realized the surprise attack and tried to lead a remaining reserve contingent in the rear of von Kapellen's troops, a maneuver that was misinterpreted as a rout by the Bohemian forces. The following collapse resulted in a complete victory of Rudolph and his allies. Ottokar's camp was plundered, and he himself was found slain on the battlefield.