In the
history of Christianity, the
first seven ecumenical councils, from the
First Council of Nicaea (325) to the
Second Council of Nicaea (787), represented an attempt to reach an
orthodox consensus and to restore, continue and develop a unified
Christendom. The
East–West Schism, formally dated to 1054, would become definitive almost three centuries after the last of these councils, but already by 787 the major western sees, although still in communion with the state church of the
Byzantine Empire, were all politically outside the Empire, and the
Pope was to crown
Charlemagne as a western emperor 13 years later.