Pope Honorius I (died 12 October 638) was the bishop of Rome from 27 October 625 to his death. He was active in spreading Christianity among Anglo-Saxons and attempted to convince the Celts to calculate Easter in the Roman fashion. He is chiefly remembered for his correspondence with Patriarch Sergius I of Constantinople over the latter's monothelite teachings. Honorius was posthumously anathematized, initially for subscribing to monothelitism, and later only for failing to end it. The anathema against Honorius I became one of the central arguments against the doctrine of papal infallibility. Early life Honorius was a rich aristocrat who came from Campania. His father was the consul Petronius. Nothing is known about Honorius I's career before he became pope on 27 October 625. He was consecrated only two days after the death of his predecessor, Boniface V. The vacancy was short probably because of the presence in Rome of Isaac the Armenian, who was empowered to confirm the election as the imperial exarch in Italy. Papacy As pope, Honorius I looked up to Gregory I and employed monks rather than secular clergy as staff at the Lateran Palace. He initially supported Adaloald, the deposed Catholic king of the Lombards, but established cordial relations with Adoald's Arian rival Arioald. He did not succeed in resolving the schism of Venetia-Istria, but took steps to appease the archbishops of Ravenna, who were dissatisfied with their subordination to Rome. Honorius actively supported the difficult Christianisation of Anglo-Saxon England and sent Birinus to convert the West Saxons, but less successful in convincing the Celts to abandon their system of computing the date of Easter. At the Sixth Council of Toledo, Honorius urged the Visigothic bishops to continue baptizing Jews, a policy instituted by Gregory I. Honorius became involved in early discussions regarding the doctrine of Monothelitism, which is the teaching that Christ has only one energy and one will, in contrast with the teaching that he has two energies and two wills, both human and divine. Patriarch Sergius I of Constantinople wrote an initial letter informing Honorius of the Monoenergism controversy, asking Honorius to endorse a position that Church unity should not be endangered by having any discussions or disputes over Christ’s possessing one energy or two. Sergius added that the doctrine of two energies could lead to the erroneous belief that Jesus has two conflicting wills. Pope Honorius’ reply in 635 endorsed this