In order to provide some background material for the Orientale Lumen Conferences in 2010, with the help of Father Michael Hayduk, I prepared a summary of the first Seven Ecumenical Councils that I post here.

SITE: Constantinople (near Bosporus, a strait in today’s Turkey).
YEAR: A.D. 381
POPE: St. Damasus I, 367 – 384
EMPEROR: Theodosius I, the Great, 379 – 395
ACTION: It appears that Pope St. Damasus I was not contacted in regard to this council attended by about 186 bishops. Called by the emperor, it was not attended by the pope or his legates or any bishops from the West. Nevertheless, it is listed as a General Council of the 4th century by papal decrees of the 6th century, by which time its doctrinal definitions were accepted throughout the Church (Murphy, pg. 41). This council condemned the heresy of Macedonius by clearly defining the divinity of the Holy Ghost: He is not created like the angels no matter how high an order is attributed to such a “creature.” The council also reaffirmed the faith of Nicaea.
NOTE: St. Gregory Nazianzen, Doctor of the Church (d. 389), was the bishop presiding. St. Cyril of Jerusalem, Doctor of the Church (d. 386), was also in attendance.
HERESIARCH: MACEDONIUS.

The First General Council of Constantinople, under Pope Damasus and the Emperor Theodosius I, was attended by 150 bishops. It was directed against the followers of Macedonius, who impugned the Divinity of the Holy Ghost. To the above-mentioned Nicene Creed it added the clauses referring to the Holy Ghost (qui simul adoratur) and all that follows to the end.