Fortunately, such things are preserved for us, as for a while now, I’ve heard that the original call for the Council of Nicaea was over the date of Easter, but Nicaea was far from just about Easter…
Letter of Emperor Constantine summoning the bishops from Ancyra to Nicaea
I believe it is obvious to everyone that there is nothing more honorable in my sight than the fear of God. Though it was formerly agreed that the synod of bishops should meet at Ancyra in Galatia, it seemed to us for many reasons that it would be well for the synod to assemble at Nicaea, a city of Bithynia, both because the Bishops from Italy and the rest of the countries of Europe are coming, and because of the excellent temperature of the air, and in order that I may be present as a spectator and participator in those things which will be done. Therefore I announce to you, my beloved brothers, that all of you promptly assemble at the said city, that is at Nicaea. Let every one of you therefore, as I said before, keep the greater good in mind and be diligent, without delay in anything, to come speedily, that each may be physically present as a spectator of those things which will be done.
God keep you my beloved brothers.
Translation from A New Eusebius, Ed. J. Stevenson (London: SPCK, 1963) no. 299, adapted by GLT
The history of this letter and its authenticity are discussed in Hanson, pp. 146-151
While there was a reason that a meeting was going to be held in Ancrya, Constantine’s intrusion reconstituted the entire Council from a lowly synod to a full blown, imperial court.
What say ye?