This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Ecumenical Assemblies gathers three of the World Council of Churches' periodic general assemblies, chosen because between them they trace how the council's own membership grew and how far its theology could stretch before testing the churches that joined it.
The First Assembly, held at Amsterdam, constituted the World Council of Churches itself out of a hundred and forty seven member churches, and it did so carefully: the constitution it adopted is council shaped but deliberately not a council, denying the body any power to legislate for its members. The Third Assembly, held at New Delhi in 1961 with 577 delegates, reshaped that founding body twice over. The International Missionary Council merged in as its Division of World Mission and Evangelism, completing the union of the ecumenical movement's two founding streams, and the council received its first Eastern Orthodox national churches from behind the Iron Curtain, the Russian Orthodox Church together with the Orthodox churches of Romania, Bulgaria and Poland, alongside nearly every other Orthodox body that had not already joined at Amsterdam.
The Seventh Assembly, held at Canberra in 1991 under the theme Come, Holy Spirit, Renew the Whole Creation, was the first assembly theme to name the Holy Spirit directly and extend the invocation to the whole of creation, with some 317 member churches represented. It is remembered less for its formal documents than for a single plenary address that tested how far that theme could be carried before it stopped sounding Christian to some delegates, which is where this grouping's own edges run: a council built to hold churches together still has to decide, assembly by assembly, how far its language can move without losing them.