Will you please cite your sources for this statement. You are inconflict with the events that happened at the synod of Constantinople in 867.
The dogma of the Filioque can be traced back to the founding fathers, and I can do so if you wish. It seems to me you pride yourself on revisionist history. There is plenty of sources that can give accurate accounts begining with this one from New Advent encyclopedia:
The dogma of the double Procession of the Holy Ghost from Father and Son as one Principle is directly opposed to the error that the Holy Ghost proceeds from the Father, not from the Son. Neither dogma nor error created much difficulty during the course of the first four centuries. Macedonius and his followers, the so-called Pneumatomachi, were condemned by the local Council of Alexandria (362) and by Pope St. Damasus (378) for teaching that the Holy Ghost derives His origin from the Son alone, by creation. If the creed used by the Nestorians, which was composed probably by Theodore of Mopsuestia, and the expressions of Theodoret directed against the nineth anathema by Cyril of Alexandria, deny that the Holy Ghost derives His existence from or through the Son, they probably intend to deny only the creation of the Holy Ghost by or through the Son, inculcating at the same time His Procession from both Father and Son. At any rate, the double Procession of Holy Ghost was discussed at all in those earlier times, the controversy was restricted to the East and was of short duration.
The first undoubted denial of the double Procession of the Holy Ghost we find in the seventh century among the heretics of Constantinople when St. Martin I (649-655), in his synodal writing against the Monothelites, employed the expression "Filioque". Nothing is known about the further development of this controversy.
Again, please cite your sources in regard to the Filioque not being a part of Christian tradition. Thanks.
Citing the acta of a synod which was anathematized by the Holy Orthodox Church does not move me. All additions to the Creed and the (pitfully attended) synod of 867 were anathematized by the Council of Constantinople in 897, which (I add for the benefit of Westerners) was accepted by the Pope of Rome at the time, John VIII.
I suggest you read the writings of St. Photius the Great on the matter. He was at least as learned as the compilers of your "New Advent" encyclopedia, though I'm sure he lacks "accuracy", which you seem to believe is synonymous with accepting the interpretation of events offered by papal apologists.