As approved in amplified form at the Council of Constantinople (381), it is the profession of the Christian Faith common to the Catholic Church, to all the Eastern Churches separated from Rome, and to most of the Protestant denominations.
A seemingly minor difference in the wording of this simple text had a profound impact on European history. The Nicene Creed, or Symbol of Faith, was written by the First Ecumenical Council at Nicaea in 325 C.E., with additions (the 3rd paragraph and following) by the first Council of Constantinople (381). There is an unresolved controversy over the words 'and the Son' (in Latin filioque). This language was added in 587 by the local council of Toledo, Spain, in an attempt to combat the Arian heresy. Pope Leo III (795-816) forbade the use of the filioque version and had it engraved without 'and the Son' on the walls of St. Peter's Basillica. After a failed attempt to unite by marriage Charlemagne's Frankish holdings with that of the Byzantine Empress, Charlemagne challenged Byzantinium's claim of universal jurisdiction as the successor to Rome by claiming in 792 that among other things, that the Byzantines had omitted the filioque from the original text. The filioque was finally accepted by the Romans in the year 1014, and the revision has been part of Catholic doctrine ever since. The "filioque," the significance of Roman primacy, and geo-political conflict led to the the Great Schism of 1053. To this day, the Eastern Orthodox Churches do not accept the filioque and raise this as one of many reasons that prevent re-unification with the Roman Catholic Church.