The Council of Serdica in Dacia was a part of the Trinitarian controversy. The matter failed to be settled at the council of Nicaea in 325 which produced a credo with the controversial term "homoousios" (consubstantial) to describe the Son-Father relation in the Trinity. One of the fiercest pro-Nicenes was bishop Athanasius of Alexandria, whom his opponents managed to sentence at the council of Tyre in 335. This decision caused controversy and there were attempts to revise it. In 341, in Rome, Pope Julius I gathered a council which overturned the sentence. Julius asked the Eastern bishops to approve this revision, but when they gathered in Antioch in 341 they failed to do that; they also issued the formulation of faith which avoided the term "homoousios", approved by the council of Nicaea. Julius I asked the emperors Constans and Constantius to convene a new council to resolve this disagreement. The council gathered in Sardica in 343 and was presided over by Hosius of Cordoba. Eastern bishops arrived but were unwilling to acquit Athanasius (and other pro-Nicenes condemned by the Eastern councils: Marcellus of Ancyra and Asclepus of Gaza) and they soon left the council and withdrew to Philippopolis where they held their own gathering. The Westerners continued the proceedings, rehabilitated Athanasius, and issued a set of disciplinary canons. These survived in two differing versions, Latin and Greek. There are 21 canons in the Latin text, and twenty in the Greek; the arrangement also slightly differs. For a detailed discussion of the council of Serdica 343 and the textual problems caused by the surviving text see: Hess 2003, Stephens 2015. See also Simonetti 1975: 161-87; Hanson 1988: 293-305.