During the archeological excavations of the Gradac Monastery complex, conducted by the Institute for the Protection of Cultural Monuments of Serbia, in the summer of 1967, on the west side of the Church of St. Nicholas, in the immediate vicinity of the defensive wall, a tile was found in the shape of an irregular square, small, only 2.7 cm x 2.8 cm and up to 1 cm thick. The tile is made of soft talc stone suitable for processing and on the upper smooth surface the inscription is engraved in short Cyrillic letters in three lines. On the back are also Cyrillic, but shallower scratched letters and two round deeper and third shallower holes. On the front is the name of the despot Lazar, on the back the monogram of Gregory, the son of the despot Đurađ Branković. Tile is extremely enigmatic for many reasons. First of all, why are the two brothers, who were political opponents, together on the plaque, especially if the holes on the back are used to attach it to an object, then Gregory’s monogram is not visible. The question is also what it was used for and why an ordinary, non-precious stone was used, while the processing is extremely simple. In any case, this unusual finding, no matter how enigmatic, indicates, with other indications, that the Branković’s played a significant role in the renovation of the Gradac Monastery in the 15th century.