Thus in a book of tracts of the thirteenth century attributed to Pope Celestine V (though the authenticity of this work has been denied) a separate tractate is given to the precepts of the Church and is divided into four chapters, the first of which treats of fasting, the second of confession and paschal Communion, the third of interdicts on marriage, and the fourth of tithes.
The identification is also considered probable by recent scholars (e.g., Hollander, Barbara Reynolds, Simonelli, Padoan).
Although the first election following Ubi periculum observed its rules and took only one day, its application was suspended and the elections of 1277, 1280–1281, 1287–1288, and 1292–1294 were long and drawn out until Pope Celestine V (another non-cardinal and relative outsider) reinstituted the law of the conclave.
Pope John Paul II | Pope Benedict XVI | Pope | Pope Paul VI | Alexander Pope | Pope Pius IX | Pope Pius XII | Pope Francis | Pope Leo XIII | Pope Pius XI | Pope John XXIII | Pope Innocent IV | Pope Pius VII | Pope Pius X | Pope John Paul I | Pope Alexander III | Pope Clement VII | Pope Urban VIII | Pope Clement V | Pope Pius VI | Pope Julius II | Pope Gregory VII | Pope Clement VIII | pope | Pope Sixtus V | Pope Alexander VI | Pope Benedict XIV | Pope Benedict XV | Pope Innocent XI | Pope Sixtus IV |