[1] Sixtus II restored the relations with the African and Eastern churches, which had been broken off by his predecessor over the question of heretical baptism raised by the heresy Novatianism.

[4] Sixtus is thought by some to be the author of the pseudo-Cyprianic writing Ad Novatianum, though this view has not found general acceptance.

[1] The Tridentine calendar commemorated Sixtus, Felicissimus, and Agapitus on the feast of the Transfiguration of the Lord, 6 August.

They remained in that position in the General Roman Calendar until 1969, when, with the abolition of commemorations, the memorial of Sixtus "and his companions" was moved to 7 August, the day immediately after that of their death.

[5] The following inscription honoring Sixtus was placed on his tomb in the catacomb of Callixtus by Pope Damasus I: At the time when the sword pierced the bowels of the Mother, I, buried here, taught as Pastor the Word of God; when suddenly the soldiers rushed in and dragged me from the chair.