The "Filioque" ("and the Son") controversy, about the words of the creed - that the Holy Spirit proceeded from the Father ("and the Son") led to the final split between the Orthodox Church and the Roman Catholic Church. Of the early attempts to heal the schism between the Byzantine and Western churches, none is as famous as the Council of Lyons, 1274. Less familiar is the Byzantine reaction that followed in the patriachate of Gregory of Cyprus, when the settlement of 1274 was formally repudiated by imperial decree and the solemn decision of the Byzantine Church at the Council of Blachernae, 1285. This work is a study of Gregory II and the Council of 1285