It happened that at the time when the letter arrived at Trani, Cardinal Humbert, a vigorous champion of ecclesiastical rights, was residing in that city, and he translated it into Latin and communicated it to Pope Leo IX.

The arguments adduced in favour of that hypothesis are that Niccola's father, though commonly believed to have been Ser Pietro da Siena, was perhaps called Pietro di Apulia,[409] and that meritorious artists certainly existed at Foggia and Trani.