General Councils
- Article from the Catholic Encyclopedia, looking at the definition, place in church governance and short historical sketches of each council until Vatican I.
- http://www.newadvent.org/cathen/04423f.htm

Fourth Council of Constantinople : 869-870
- This was the first council that was not recognised as canonical by either Protestants or Orthodox authorities.
- http://www.piar.hu/councils/ecum08.htm

All Ecumenical Councils - All the Decrees
- A list of Catholic ecumenical councils and their decrees.
- http://www.piar.hu/councils/

Vienne, Council of
- Convened 1311-1312 dealing mainly with the Knights Templars.
- http://www.newadvent.org/cathen/15423a.htm

The Ecumenical Councils of the Roman Catholic Church
- A list of summaries of the main facts of each recognised council.
- http://www.catholicism.org/pages/ecumenic.htm

The Church in Crisis A History of the General Councils - AD 325 through AD 1870
- Text of the 1960 book by Monsignor Philip Hughes giving an historical background and an account of the proceedings of all the main Catholic ecumenical councils until Vatican I.
- http://www.christusrex.org/www1/CDHN/coun0.html