This council was centred around whether Photius ought, or ought not, to be Patriarch of Constantinople. It involved clear political interactions and, what is more, the political situation was complex, and changed significantly over short periods of time. An interaction with actual ‘secular’ politics and civic life is a feature of many of the ecumenical councils. An awareness of political factors is probably common to them all. After all, the Church exists in and interacts with the world. In common with other councils, it passed canons that have proved important over time, and often of more significance and use in theology, than the central business for which such councils were principally called.
The events linked to this council fell within a longer period of tension and suspicion between the Latin Western Church and Greek Eastern Church. The affair began when Nicholas I was pope (858-867). In Constantinople Michael III was emperor: he was born in 840 and had reigned from 842. In 858 Ignatius (b. 797) became Patriarch of Constantinople. He refused Michael Holy Communion on grounds of incest. Michael retaliated by deposing him and selecting a brilliant and devout layman, Photius (b. 810), to be patriarch. He went through the requisite set of ordinations and was consecrated patriarch in 5 days was but these actions did not adhere to the normal canonical procedure of the day. Both Ignatius and Michael appealed to the Pope. After conducting an investigation, Pope Nicholas accepted Ignatius as the still valid patriarch and he deposed and excommunicated Photius. However, de facto, Photius continued to have power as patriarch in Constantinople.
The situation worsened, and letters were sent by both camps denouncing the other. Then in 867 Photius called and presided at a council that declared Pope Nicholas excommunicate and deposed him. Nicholas died before hearing the results, the new pope being Hadrian II, (867-72). But events in Constantinople then also took a dramatic turn.
Emperor Michael had a co-emperor, Basil I, from 1866 who in 1867 then murdered Michael and so gained complete control as Emperor. He acted quickly to depose Photius and to reinstate Ignatius as patriarch. Basil asked Pope Hadrian to join him in a new council to tidy things up. This was held in Constantinople in 869-70 (and is the council the West later recognised as an ecumenical council). It was held from October 5th to February 28th 870, and met in 10 sessions, and by its last session it included 102 bishops, 3 papal legates and 4 patriarchs, though it began with far fewer attendees. Its main purpose was to condemn Photius for his acts in 867 and to depose him. It also took steps against his decisions, appointments and actions as patriarch. It issued 27 canons (in the Latin records). It restored the honour of Pope Nicholas I and recognised his actions. In general it conveyed a high view of the papacy, but also recognised Constantinople as the second see of the Church, after Rome. In strong terms it criticised imperial interference in the appointment and consecration of bishops and other Episcopal matters, as in the elevation and rapid set of ordinations of Photius. It also reaffirmed the use of icons as stated in Nicea II.
Patriarch Ignatius died in 877 and Photius became patriarch, this time in a situation and way that the Pope could also now accept as valid. A council of the East was held in 879-80, again in Constantinople, to consolidate the position of Photius. He confessed his errors of 867 in excommunicating the pope. The papal legates took the documents back to Rome. It appears that Pope John VIII (872-882) then recognised Photius, seemingly revoking the council of 869-70 in regard to decisions specifically about Photius, but not in regard to its more general terms or canons. In a way, within 10 years the specific issue that the council of 869-70 addressed had been resolved. Photius continued as patriarch until 886, finally dying in 893.
Neither the council of 869-70 or that of 879-80 were regarded as ‘ecumenical’ at or soon after the time. In the late 11th century, at a time when the papacy was seeking to assert its rights over Episcopal appointments and investiture in the West, in opposition to claims by (Holy Roman) emperors and kings. To support these claims, it recognised the council of Constantinople of 869-70 as Ecumenical, ie as Constantinople IV, since the canonists and, more importantly, then the pope judged its canons against political interference in Episcopal appointments to be of universal importance for the Church. The core issue that led to its recognition, long after its occurrence, as ecumenical, was the autonomy and the independence of the Church, and, with it, a process of integrity in the appointment of bishops and in the motivation of candidates. These principles have been threatened a number of times across church history, and have repeatedly been addressed by ecumenical, and other, councils.
The council of 869-70 was not accorded ecumenical status to slur the memory of Photius. But the Eastern Churches have tended to see it that way. They regard the council of 879-80 as the more important one, and it was the one that allowed matters to settle down at the time. The overall impact of Photius through his whole life and writings made him one of the most influential figures in the history of the Byzantine Empire. Interestingly both he and Patriarch Ignatius became recognised as saints in the East. Only Ignatius is recorded in the Roman Martyrology. Pope Nicholas I is known as St Nicholas the Great.
The Eastern (Greek) Churches do not accept the ecumenical nature of Constantinople IV (869-70) or of later councils recognised by Popes. In general they only accept as ‘ecumenical’ the 7 councils that were so recognised from Nicea I (325) to Nicea II (787). The Church, gathered around, and in unity with, Peter and his successors, has come to the view that in the final analysis, the pope has to decide what is, and is not, an ecumenical council, and which of its decisions are binding on the whole church and (depending on their nature) for how long. The events around Photius and Constantinople IV, the canons it produced, and reflection on all this, were part of the process that led to this understanding of how authority works within the Church, guided by the Holy Spirit. (The reception of such teachings and decisions by the wider Church, and their theological interpretation and application are also important.) The events around Constantinople IV also illustrate that the Holy Spirit works amidst political complexity and through human agents, whose conduct cover the gamut from weak to strong, foolish to wise, and sinful to saintly.
(The illustrations are, in descending order, images of Saints Nicholas, Ignatius and Photius.)