An Ecumenical Council (also sometimes Oecumenical Council) or general council is a meeting of the bishops of the church of the whole world who have come together to discuss matters of Church doctrine and practice.
The word is from the Greek language "Οικουμένη", which means "inhabited", and was originally an other name for the territory of the Roman Empire, because the earliest councils were all called in by Roman Emperors. In later times it was used in the sense of "world-wide" or "general."
Quinisext Council (= Fifth and Sixth) or Council in Trullo, (692); this council is accepted by the Eastern Orthodox Church as a part of the Third Council of Constantinople, but is rejected by Catholics.
7. Second Council of Nicaea, (787); restoration of the veneration of icons and end of the first iconoclasm. It is rejected by many Protestant denominations, who instead prefer the Council of Constantinople of 754, which condemned the veneration of icons.