Decisions at ecumenical councils required ‘unanimous’ consensus. This paper treats two councils, Constantinople III (680–81) and Constantinople IV (869–70), which issued decrees where the claim to unanimity was particularly contrived. Although the Acts of Constantinople III try to hide the fact, the account in the Liber pontificalis shows that it took imperial pressure and months of debate before the bishops of the patriarchate of Constantinople came over to the ‘orthodox’, dyothelete side. At Constantinople IV the lack of support for its anti-Photian decrees is shown by minimal number of bishops who chose to attend. These two councils are examples of ‘ecumenical’ decisions that, so far from being unanimous, enjoyed the genuine support of only a minority.
The Council of Constantinople of 869 was convoked by Emperor Basil I on the demand of pope Hadrian II aiming at concluding the causa Ignatiana et Photiana, actually at the definite condemnation of Patriarch Photius and his followers. The Council in Western historiographical and canonical tradition labelled as the Eighth Ecumenical Council, was in fact a minority council. The instruction of Pope Hadrian II to his representatives in Constantinople that they should collect handwritten libelli emendationis or satisfactionis by all invited bishops as a conditio sine qua non for being permitted to participate at the Council, forced hundreds of invited bishops to choose – with the exception of merely 102 of them – to abstain from participation.