The First Council of Nicaea
Why I should think this is a good event to chart in astrology may be dependent on what that chart shows. It was a council convened by Constantine to get the bickering bishops of his newly recognized state religion to agree on first principles. His influence was tantamount to taking over control, but he managed to get the majority of them to come to a consensus of sorts in the months that followed.
The first thing that stands out is the Grand Cross forming out of the Leo Ascendant (Constantine). The Bishops are represented by the conjunction (stellium) of Moon/Jupiter/Uranus in Aquarius, with Pluto joining in at the end. The Moon represents the Gnostics; Jupiter, the Orthodox; and Uranus, the ‘modern’ Western Church. The other arm of the cross is an opposition between Mercury (logic) and Neptune (intuition).
The extended Jupiter/Uranus/Pluto conjunction is supported by Saturn (the State). And Mercury is supported by Mars (the Roman Military might). The Sun is square to Pluto (and just for fun, I’d like to suggest that this is a conflict between Jesus and Satan.)
Only Venus (love) is unaspected.
There is only one inconjunct:
Moon Inconjunct Mars
Until you learn to handle your feelings, you are likely to get very angry easily, have temper tantrums and be touchy about what is yours and what is not. You may feel you have to defend yourself against imagined threats. The problem here is that you are likely to become too emotionally involved with ideas, opinions or even objects without knowing it until someone threatens them. Then you react as if you were being personally threatened or attacked. You have to realize that it is possible to change your opinions and attitudes without damaging your worth as a person.
The truth is this is the time when the Christian Church split into three: Western Church; Eastern Orthodox; and the Gnostics. Over time, only two of these schisms remained. The third way was completely wiped out by Holy Crusades in the 13th century.