I think you might be asking, "What was the council of Nicea?" If I am correct, I'll tell you. It was a council of men, gathered together in 325 ad at the bequest of Roman Emperor Constantine. Its purpose was to make and create a standardize holy canon and binding doctrine for the movement known as Christianity.
So he gathered men, from the early Christian community leaders, and a few Pagan leaders to organize the writings of Jesus Christ's disciples, Christ stories and teachings all into a book. It established "Christian law", and set forth the motion that the Pauline doctrine would be the standardize teachings of Christian thus forth, instead of the teachings of the Essenes or Ebiontes. I believe, there were two more council of Nicea's, which was in Turkey by the way, convened after that first meeting in 325ad. It truly laid the foundational stepping stones for the Roman Catholic Church, and the beginnings of Catholicism.
With that said, it was this first council which became the stepping stone that eventually divided the Eastern Church (those whom followed Jesus brother James) vs. Western Christian ideology, the Coptic Christian movement, the Ethiopian/African Christianity movement and the Gnostic movement. It was Constantine's hope, (at least that is what I believe) that those sects would gather under his one church charge- thus, they did not. But that's the council of Nicea in a nutshell. Great question.