The canons were approved by all but two of the attendees, which likely numbered 318 bishops from across all of Christendom, including bishops from outside of the Roman Empire (such as Persia), and two personal representatives of Pope Sylvester, who remained pope for about 20 more years. Further, the Nicene council took up similar issues as the Alexandrian council of just four years earlier, which was conducted without influence from Constantine.
So what authority would Constantine have over Persian bishops, that could justify it being said that the council was held “under Constantine”?
Evidence please. Real evidence, not legend.
Who called this Council? The First Ecumenical Council. It certainly wasn't the Pope was it?
Pope St. Sylvester I (314-335)
This was the era of Constantine the Great, when the public position of the Church so greatly improved, a change which must certainly have been very noticeable at Rome ; it is consequently to be regretted that there is so little authoritative information concerning Sylvester's pontificate. At an early date legend brings him into close relationship wtih the first Christian emperor, but in a way that is contrary to historical fact.
Still it is not certain whether Constantine had arranged beforehand with Sylvester concerning the actual convening of the council, nor whether there was an express papal of the decrees beyond the signatures of the papal legates (cf. Funk in "Kirchengesch. Abhandlungen und Untersuchungen", I, 95, 501 sq.).
Catholic Encyclopedia - Pope Sylvester I
Your argument is with the Catholic Encyclopedia, not me.
I didn’t cite legend; I carefully avoided, and I didn’t cite various sources that the Catholic Encyclopedia is rejecting... and if anything you have to allow that the Catholic Encyclopedia does try to be highly objective, and even frequently fails to contest the prevailing view in 1917, protestant-dominated America.
So, OK, you post how the Catholic Encyclopedia cites that hard, reliable documentation is lacking, because some of the documentation is unreliable. Fine. But the Catholic Encyclopedia also asserts, with the same objective sensibility:
* The characterization of the Council of Alexander as a fore-runner of Nicea, without any Imperial influence,
* The non-imposing invitations of Constantine
* The universal nature of the council, including cultures beyond the influence of the Emperor
* The lack of contest over the assertions of the council, and eventual universal acceptance, with only two dissident Bishops
* The domination of the council by non-Latins, whom Constantine would have less influence over
Given the immediate, universal acceptance of Nicea, including in areas beyond the reach of Constantine, it isn’t up to me to assert Rome’s approval of the Council, it’s up to you to cast doubt on it. Far from sowing discord with the imposition of novel doctrines, Nicea settled nearly any and all disagreement, and Aryanism, adventism, quattrodecennialism, all quickly and, in contrast to the pre-Nicene situation, peacefully waned.