Proving the correct interpretation and date of the murals in the ducal rotunda of St. Catherine in relation to the completion of the construction of the building lies within an historical event. On Pentecost in 1134, on the occasion of the baptism of the second son of the prince Sobeslaus I, a wedding was agreed between Conrad II of Znojmo, and Mary of Serbia, sister of the Hungarian Queen. The pact between Sobeslaus I. and Conrad II. of Znojmo, concerning the future ascension of Conrad II of Znojmo to the throne of the principality of Prague, was to have been reinforced through this marriage. Conrad II of Znojmo had also recently regained power in the territory, which belonged to him through family title.