ɪn wˈʌn θˈaʊzənd wˈʌnhˈʌndɹɪd sˈɛvənti sˈɛvən, hiː wʌz wˈʌn ʌvðə tʃˈiːf nᵻɡˈoʊʃɪˌeɪɾɚz ʌvðə tɹˈiːɾi ʌv vˈɛnɪs bᵻtwˌiːn ˈɛmpɚɹɚ ænd pˈoʊp, ɪnwˌɪtʃ ðɪ ˈɛmpɚɹɚ fˈɔːɹməli ɐknˈɑːlɪdʒd ˌælɪɡzˈændɚɹ æz pˈoʊp ænd ɐbˈændənd hɪz ˈoʊn ˌæntɪpˈoʊp, kˈælɪstəs ɹˌoʊmən θɹˈiː.
In 1177, he was one of the chief negotiators of the Treaty of Venice between Emperor and Pope, in which the Emperor formally acknowledged Alexander as pope and abandoned his own antipope, Callistus III.