The article sheds light on the subject and attribution of the sketch in the collection of the Royal Canonry of Premonstratensians at Strahov (oil, canvas, 100 x 70 cm, exhibited at the National Gallery in Prague). For a long time, the sketch was considered to be the work of Václav Vavrinec Reiner. It is, however, a ricordo connected with the painting decoration of the Corpus Christi Chapel, which is part of the former imperial boarding school in Olomouc. The painting decoration of the chapel was executed in 1728 by the Olomouc painter Jan Krystof Handke (1694-1774), who also produced the sketch. The painting represents the celebration of the Blessed Sacrament and a motif from the legend of the miraculous victory of Jaroslav of Sternberk over the Tartars in the battle at Olomouc. As has already been noted, the Jesuits helped to popularise the legend; they also added to it the motif of the miracle of the Eucharist. Yet it seems that it was Spanish members of the Olomouc college of the Society of Jesus who, as early as 1600, adapted the Eucharist motif of the medieval legend from the Aragon city of Daroca to the Olomouc setting. They thus clearly hoped to incorporate the Moravian legend into the context of other Eucharistic miracles, which occurred around the middle of the 13th century in various remote locations in Europe and which led to the establishment of Corpus Christi Day in 1264. The choice of motif for the decoration of the chapel, emphasising the importance of holy communion, also celebrates chivalrous honour and valour. It may have been influenced by the contemporary debate about the future of the Jesuit boarding school, which was waged in Olomouc in the 1720s, in connection with the founding of the new academy of the Estates.