The paper presents fragments of a Byzantine icon discovered in 2015 during regular archaeological excavations carried out in Chełm, eastern Poland. Iconographic analyses allow the nine surviving fragments to be interpreted as belonging to a diptych wing with the Great Feasts cycle. The icon represents archaic iconography of the subject, with the scene of Transfiguration placed after Entry into Jerusalem and before the Crucifixion. The artefact was created in the second half or at the close of the 12th century, and it was made from steatite, which has been confirmed by petrographic analyses. The icon was discovered in the remains of a palace complex of King Daniel Romanovich, the greatest ruler of the Galicia-Volhynia Lands. The results of the archaeological research allow the terminus ante quem for the icon’s arrival in Chełm to be determined as before the middle of the 13th century. Various possible explanations as to how the icon found its way to Chełm are also explored in the paper.