I.
The first Council of Lyon was the renewed attempt of Pope Gregory IX to oppose Emperor Frederick Hohenstaufen after the emperor had forestalled a council convoked in Rome by Gregory in 1241. His successor ¶ Innocent IV succeeded in evading the power of the emperor and on Jan 3, 1245, convoked a council in Lyon to clarify the relationship between pope and emperor, take measures against the Tartars, and find help for the Byzantine Empire and the Holy Land. The council held three sessions from Jun 26 to Jul 17, 1245; there…