Early Church Documents:
COUNCILS OF THE CHURCH

From: The Ecole Initiative – Karen Rae Keck and Norman Hugh Redington, 1996. (project now defunct)
Heavily revised (with updated links) by Nikita Simmons, 2009.

Sources:

CCEL – Christian Classics Ethereal Library: NPNF2-14. The Seven Ecumenical Councils. (This book may also be downoaded as a PDF if you choose to register.)

NA – New Advent Catholic Encyclopedia (1913 edition, in the public domain). While this is a Roman Catholic resource, there is a wealth of information on the Early Church, including the subjects of Patristics and Church Councils. For an index to the Councils, see: The Fathers of the Church

SMD – St. Michael's Depot – an Australian site which is now defunct, but is maintained (mirrored) by a Roman Catholic site in Hungary: All Ecumenical Councils - All the Decrees. See also: Papal Encyclicals Online, which has likewise salvaged material from St. Michael's Depot.

SPL – St. Pachomius Library. A First Draft for a Living Encyclopædia of Orthodox Christianity. See: Councils of the Church

Councils of the Church before 1054: