This is just basic stuff posted on Wikipedia. It could be wrong. I don’t see anything inconsistent with my position on Pope Honorius and that of Vatican I. I would be interested to know if the anathema was ever retracted.
Wikipedia:
More than forty years after his death, Honorius was anathematized by name along with the Monothelites by the Third Council of Constantinople (First Trullan) in 680. The anathema read, after mentioning the chief Monothelites, “and with them Honorius, who was Prelate of Rome, as having followed them in all things”.
Furthermore, the Acts of the Thirteenth Session of the Council state, “And with these we define that there shall be expelled from the holy Church of God and anathematized Honorius who was some time Pope of Old Rome, because of what we found written by him to [Patriarch] Sergius, that in all respects he followed his view and confirmed his impious doctrines.” The Sixteenth Session adds: “To Theodore of Pharan, the heretic, anathema! To Sergius, the heretic, anathema! To Cyrus, the heretic, anathema! To Honorius, the heretic, anathema! To Pyrrhus, the heretic, anathema!”
This condemnation was subsequently confirmed by Leo II (a fact disputed by such persons as Cesare Baronio and Bellarmine,[4] but which has since become commonly accepted) in the form, “and also Honorius, who did not attempt to sanctify this Apostolic Church with the teaching of Apostolic tradition, but by profane treachery permitted its purity to be polluted”. The New Catholic Encyclopedia notes: “It is in this sense of guilty negligence that the papacy ratified the condemnation of Honorius.” That is, the papacy condemned Honorius not for teaching a heresy ex cathedra, but for negligently permitting heretical positions to stand alongside orthodox ones.
This anathema against Honorius was later one of the main arguments against Papal infallibility in the discussions surrounding the First Vatican Council of 1870, where the episode was not ultimately regarded as contrary to the proposed dogma. This was because Honorius was not considered by the supporters of infallibility to be speaking ex cathedra in the letters in question (although the Catholic historian Hefele and opponents of the definition believed that Honorius had spoken ex cathedra),[1] and he was alleged to have never been condemned as a Monothelite, nor, asserted the proponents of infallibility, was he condemned for teaching heresy, but rather for gross negligence and a lax leadership at a time when his letters and guidance were in a position to quash the heresy at its roots.