The Decretals of Gregory IX Latin, Decretales Gregorii IX , also collectively called the Liber extra, are an important source of medieval Canon Law In 1230, Pope Gregory IX ordered his chaplain and confessor, St Raymond of Pe aforte Pennafort , a Dominican, to form a new canonical collection destined to replace all former collections It has been said that the pope by this measure wished especially to emphasize his power over the Universal Church.After the invention of printing, the Decretals of Gregory IX were first published at Strasburg from the press of Heinrich Eggesteyn.