Franciscan martyrs of Vilnius are 14 semi-legendary Franciscan friars murdered in Vilnius, capital of the Grand Duchy of Lithuania, during the reign of Algirdas (1345–77). The story was first recorded in the Bychowiec Chronicle, a generally unreliable source from the early 16th century, and was further embellished, conflated, and confused by later chroniclers and historians. Nonetheless, the cult of the martyrs spread in the 16th century. A prominent monument in Vilnius, the Three Crosses, was originally erected in their memory sometime before 1648. Around the same time Bishop Jerzy Tyszkiewicz started canonization procedures, but they were abandoned. At the advent of critical historiography in the 20th century, the story was dismissed as fictional in its entirety. However, newer research attempts to restore some credibility to the legend.