Latin, meaning “and [from] the son.” In the sixth century, Arian barbarians (Goth and Visigoth) invaded the western empire and introduced many heretical dogmas and expressions. In 589 a.d., the Council of Toledo included details in the Creed concerning the procession of the Holy Spirit from and the Son in order to emphasize the divinity of Christ. This addition of “and the Son” () was accepted by the West before this council.

In the seventh century, the became a matter of debate between the East and the West, when Patriarch Photius of Constantinople raised the issue within the empire, and it was only in the ninth century that the Western world responded. In the 11th century, the Franks imposed on the and the West, while the East rejected it, hence resulting in a between the East and the West.

The Coptic Church, then under Islamic dominance and having been separated from imperial Christianity since the Council of Chalcedon in 451 a.d., did not take part in the debate, which caused a between the two Chalcedonian strongholds in Rome and Constantinople.