Clavius would later write defences and an explanation of the reformed calendar, including an emphatic acknowledgement of Lilius' work.

He attended the University of Coimbra in Portugal, where it is possible that he had some kind of contact with the famous mathematician Pedro Nunes (Petrus Nonius).

[8] As an astronomer Clavius adhered strictly to the geocentric model of the solar system, in which all the heavens rotate about the Earth.

However, in 1580 in his document titled Ordo servandus in addiscendis disciplinis mathematicis, Clavius described a detailed curriculum for mathematics to have the College officially recognize the Academy.

Clavius made another attempt in 1586 to establish the Academy as an official course at the Collegio Romano, but there was opposition from the philosophers at the College.

Clavius taught the advanced course within the Academy, but little is known about his specific teachings and work as a professor during his time at the College.

There has been no evidence to show whether the students he taught shared classes or the specific material he chose to cover.

However, due to the lack of mention of mathematicians in the College's catalog after 1615, it appears the Academy's official recognition by the Collegio Romano ended soon after Christopher Clavius's death.