During the late Middle Ages and the Renaissance, representatives of the Chaldean community visited Rome seeking contact with the mother church. Abdisho IV of Gazarta, newly elected Patriarch of Mosul, made the journey in 1562. According to Pietro Strozzi, De dogmatibus chaldaeorum (Roma: Zanetti, 1617), Abdisho's portrait was included in Giuseppe Porta's depiction of the Peace of Venice in 1177 in the Sala Regia of the Vatican Palace, circa 1565. The inclusion of Abdisho's anachronistic portrait in Porta's fresco can be linked to plenitudo potestatis, that is, submission to the authority of the pope. Abdisho's journey to Rome coincided with the Council of Trent, the intensified study of oriental languages, and advances in print technology. This case study reveals the global reach of papal Rome but it also shows how eastern Christians in the grip of religious and political crises engaged in dialogue with Europe.