The Filioque

Doctrine · On the Spirit · from 589

The Holy Spirit proceeds from the Father and the Son.

One word added to the creed at Toledo in 589, against Arianism and not against the East. It travelled with the Frankish liturgy; Leo III affirmed the doctrine while refusing the interpolation and had the creed engraved without it on silver shields at St Peter's. Rome sang it anyway from 1014.

Part of The Spirit proceeds from the Father.

Held it

589 — The Third Council of Toledo (Defines). Adds the word to the creed recited against Arianism at the conversion of the Visigoths. A History of the Councils of the Church from the Original Documents · Hefele, book 15, on the Third Council of Toledo
1014 — The Roman Catholic Church (Holds). Sings the creed with the word at Rome from the coronation of Henry II. East and West: The Making of a Rift in the Church · Chadwick, ch. 2

Refused it

867 — Photios I of Constantinople (Rejects). Argues that the addition makes two causes in the Trinity, and that no local church may alter the creed of an ecumenical council. The Orthodox Church in the Byzantine Empire · Hussey, part 1, on the Photian schism
1054 — The Eastern Orthodox Church (Rejects). Names the addition first among the charges of 1054. The Orthodox Church in the Byzantine Empire · Hussey, part 2, on the events of 1054

Allowed it on their own terms

809 — Pope Leo III (Permits as opinion). Affirms the doctrine and refuses the interpolation, having the creed engraved without the word on silver shields at St Peter. East and West: The Making of a Rift in the Church · Chadwick, ch. 2

In the disputes

The Filioque dispute One word added to the creed in Spain against Arianism, carried north with the Frankish liturgy, refused at Rome for two centuries and sung there from 1014.
The Great Schism The quarrel of 1053–54 was about unleavened bread and the creed, argued by legates whose commission had lapsed with the pope who sent them.
The Photian schism A disputed succession at Constantinople became a quarrel about who may judge it, and then about the creed and the mission to Bulgaria.

First stated in this form after East and West: The Making of a Rift in the Church · Chadwick, ch. 2.