A name given to the narratives of the martyrs' trials and deaths. They may be classified as follows:

Besides these divisions there are documents, whose historicity has little or no value, romances, with a possible foundation of truth, and real forgeries. There has been considerable critical studies of these Acta. The result of these investigations has been to substantiate such main facts as the causes of the persecutions, the number and heroism of the martyrs, the popularity of their cultus, and the historicity of the popular heroes.