Christians, know your lineage

[Oldandeasilyconfused]

These two were actually one church until the 11th century

Are you sure?

Isn't the Greek Orthodox Church part of/ an offshoot from the Byzantine church in Constantinople?

I was under the impression the schism goes back to the First Council Of Nicea, (325 ce)when the Canon was set and Rome (and the Pope of Rome) was declared the head of Christianity. The Christians of Constantinople did not (and do not) use exactly the same canon and did not (and do not) recognise the Pope as head of the Church. (??)

Or have I gone and gotten all confused again?