Nicea I
When and where
325 AD in Nicea (Now Iznik, Turkey,
70 miles from Constantinople on
  the Asiatic shore of the Bosporus)
Crisis or controversy
Christ was a pure creature; made out
of nothing; liable to fall;
the Son of God by adoption, not
God by nature: Arianism
Attendees
318 bishops;
Convened: Constantine I, Emperor;
Eusebius of Caesarea, historian;
St. Athanasius, theologian;
Ratified: Silvester I, Pope.
Decrees and resolutions
The Nicene Creed;
The Consubstantiality of the Word: homousion with the Father;
Solved how the date of Easter should be calculated.