He became interested in ancient history, and quickly began studying epigraphy and architectonics. As part of this interest, Maggi accumulated a large collection of ancient tombstones, including ones from Como, Ravenna, Rieti, Foligno, Perugia and Rome. In Pisa, where he was still engaged in formal studies, and in other Italian cities, he visited and examined sepulchres and sarcophagi, and used his growing knowledge to dispute a universally accepted belief of the time: the idea of the existence of giants in ancient days. All of this work formed the bases for his tractatus on sepulchres. He worked diligently to provide correct interpretations of ancient works of Roman law and, for his successful explanation of a section of the Pandects of Justinian, as he himself tells the story, he was embraced and kissed by Robertello. In Pisa, he probably obtained his doctoral degree in 1546, and returned to his native land two years later.