To add something else to the conversation as an Orthodox Christian, the irony is that while Catholics are more similar to us Orthodox people at least externally than Protestants are, Catholics are also considered schismatic, heretical, and anathema by the canons of the Orthodox Church whereas Protestants with the exception of John Calvin do not have any anathemas against them. The reason is because Rome willingly committed schism in AD 1054 from the rest of the Church whereas Protestants never belonged to it in the first place and are thus innocent as far as that goes. One of the Church's main canonical charges against Rome is the latter's addition of the Filioque to the Nicene Creed. The canons of I believe the 2nd and 3rd Ecumenical Councils--along with an 8th Ecumenical Council that pre-schism Rome accepted before later repudiating it as a "robber council"--prohibited the alteration of the Nicene Creed except by another Ecumenical Council, declaring anyone who does so anathema. The Filioque was not added by another Ecumenical Council. It was added by a backward synod in Spain at the 3rd Council of Toledo in AD 587, without the participation or approval of the rest of the Church at large. That said, the canons only prohibited the [u]alteration[/u] of the Nicene Creed; not the usage of an altered Creed (unless I missed something). Therefore technically, the Roman Catholic Church is anathema by the canons of the Eastern Orthodox Church whereas Protestants who use the Western Nicene Creed with the Filioque are not anathema since they weren't the ones who made the alteration. The greater irony is that prior to the schism, even though Rome was the one that was anathema by the canons, it was Rome that waged charges against the Eastern Church for our refusal to adopt the Filioque, whereas previously we just turned a blind eye to Rome's uncanonical addition of the Filioque. This is why the first Eastern criticism of the Filioque didn't come until the 9th century with St. Photios the Great, because it wasn't until then that Rome--influenced by the development of the papacy under Charlemagne who hated Greeks--tried to force her authority on the other patriarchates. So yes, even though Roman Catholics are, at least externally, more similar to the Eastern Orthodox Church than Protestants are, the irony is that they are also guiltier at least by virtue of technicality due to the canons of the Eastern Orthodox Church, whereas there are no canonical condemnations or anathemas against Protestantism with the exception of John Calvin. To make it worse, feelings between Orthodox people and Catholics in Europe have been very tense and bad historically. The former hold a lot of grudges against the latter because N@zi sponsored Uniate/Eastern Catholic groups during World War II used to massacre Orthodox people. There are stories of large groups of civilians being asked to Cross themselves by these groups, and the ones who would Cross themselves from right-to-left--the Orthodox--would be shot while the left-to-right Uniates would be spared. In turn, Orthodox people in recent times have acted out against Eastern Catholics, like Russia's current intervention in Ukraine for example.