In this work, we present the results of radiocarbon (14C) dating of three historically important objects related to the period of the reign of the Ottoman Empire in Europe. The following objects from the museum collection of the Franciscan Monastery in Fojnica, Bosnia and Herzegovina were 14C dated: (1) paper from the Ahdname (Fojnička ahdnama); (2) textile of the mantel of Fra Anđeo Zvizdović; and (3) paper from the Fojnica Armorial (Fojnički grbovnik). It was assumed that the Ahdname was issued in AD 1463 by the Ottoman Sultan Mehmed II to the Catholic monks and that the Mantel had belonged to Fra Anđeo Zvizdović, who received the Ahdname. The Fojnica Armorial is an important source of the classical heraldry of the Balkans Peninsula, with various estimates of the age. The 14C calibrated ages of the Ahdname are as follows: lower part, cal AD 1430–1465, upper part, cal AD 1665–1808, proving that only the lower part of the Ahdname was original. The 14C calibrated age of the textile from the outer layer of the Mantel is cal AD 1492–1641, somewhat younger than expected, and inner lining even younger, cal AD 1652–1805. Good coincidence between the calibrated age span of the renewed part of the Ahdname and the lining material of the Mantel can suggest that both objects had been renewed around the same time. Two samples of the Fojnica Armorial were dated: thick paper, cal AD 1631–1667 and thin paper, cal AD 1809–1926, showing that the Armorial had been compiled during different periods.