The claimants to the Prague throne sought for formal recognition by the Holy Roman Emperor, when in actuality, the accession required the active support by the Bohemian nobility.

The Přemyslid duke Vladislaus I of Bohemia, ruling since 1109, likewise had to struggle to consolidate his authority, defying the claims raised by his brother Bořivoj II who had reached his enfeoffment by Emperor Henry IV in 1101.

When Vladislaus died in 1125 his succession was disputed among his surviving brother Soběslav I and his Moravian cousin Otto II, duke in Olomouc and Brno.

A vanguard of about 200 heavy armoured knights commanded by Otto the Black was immediately attacked by Bohemian forces in a narrow valley, while the main army under King Lothair found itself entrapped with no option to withdraw back to the mountain pass.

To commemorate his victory, he had a rotunda built on top of the Říp Mountain and consecrated by the Olomuc bishop Jindřich Zdík, one of the oldest Czech national monuments.