In my claim I have the higher number in attendance at 318
Wikipedia: First Council Of Nicaea
Constantine had invited all 1,800 bishops of the Christian church within the Roman Empire (about 1,000 in the east and 800 in the west), but a smaller and unknown number attended.
Eusebius of Caesarea counted more than 250,
[22] Athanasius of Alexandria counted 318,
[11] and
Eustathius of Antioch estimated "about 270"
[23] (all three were present at the Council). Later,
Socrates Scholasticus recorded more than 300,
[24] and Evagrius,
[25] Hilary of Poitiers,
[26] Jerome,
[27] Dionysius Exiguus,
[28] and
Rufinus[29] recorded 318. This number 318 is preserved in the liturgies of the
Eastern Orthodox Church[30] and the
Coptic Orthodox Church of Alexandria.[
citation needed]
Delegates came from every region of the
Roman Empire, including
Britain, and from the Christian churches extant within the
Sassanid Empire.
[31] The participating bishops were given free travel to and from their
episcopal sees to the Council, as well as lodging.
Wikipedia: Constatine The Great
His most famous building projects include the
Church of the Holy Sepulchre and
Old Saint Peter's Basilica. In constructing the Old Saint Peter's Basilica, Constantine went to great lengths to erect the basilica on top of St. Peter's resting place, so much so that it even affected the design of the basilica, including the challenge of erecting it on the hill where St. Peter rested, making its complete construction time over 30 years from the date Constantine ordered it to be built.
The reign of Constantine established a precedent for the emperor to have great influence and authority in the early Christian councils, most notably the dispute over
Arianism. Constantine disliked the risks to societal stability that religious disputes and controversies brought with them, preferring to establish an orthodoxy.
[229] His influence over the Church councils was to enforce doctrine, root out heresy, and uphold ecclesiastical unity; the Church's role was to determine proper worship, doctrines, and dogma.
[230]