The '''Encyclical of the Eastern Patriarchs''' was a letter sent in May, [[1848]] by the [[patriarch]]s of the [[Orthodox Church]] in reply to Pope Pius IX's ''Epistle to the Easterns'' ([[1848]]). Rather than being a private letter to Pius IX, it is addressed to "All the Bishops Everywhere, Beloved in the Holy Ghost, Our Venerable, Most Dear Brethren; and to their Most Pious Clergy; and to All the Genuine Orthodox Sons of the One, Holy, Catholic and Apostolic Church."
The encyclical explicitly denounces the [[Filioque|Filioque clause]] added by Rome to the [[Nicene-Constantinopolitan Creed]] as a [[heresy]], censures the [[papacy]] for missionizing among Orthodox Christians, and repudiates [[Ultramontanism]] (papal supremacy). It also describes the [[Roman Catholic Church]] as being in [[apostsasyapostasy]], [[heresy]], and [[schism]].
In the course of all this, it notably makes reference to the [[Eighth Ecumenical Council]] ([[879]]-[[880]]), in contrast with the opinion of many modern Orthodox Christians that there are only seven [[Ecumenical Councils]] accepted by the [[Orthodox Church]].