The oldest preserved manuscripts of the “Story of the Rus’ian Script” date back to the 1470s. In Poland, this text is known thanks to the mention of St. Adalbert and his activity “in Moravia, Bohemia and among the Poles”. According to the story contained therein, these lands were to be christianized by Cyril and Methodius in the spirit of Byzantine Orthodoxy, only later eradicated by Adalbert. The presence of this motif, unknown from other sources, was explained by researchers as political tension between the Principality of Moscow and the Kingdom of Poland–Lithuania. However, such an approach does not explain the origin of the 15th–century writer’s belief in the influence of the supposed Methodian mission on the Piast lands nor its decline as the presumed consequence of St. Adalbert’s mission. The latest research focusing on the intellectual formation of St. Adalbert suggests that this question cannot be reduced to an unjustified stereotype. Referring to these findings and the new perspective on the "Story of...", an attempt will be made to explain the presence of the Piast thread in it.