He was baptized as "Francesco Ignazio Vincenzo" since he was born of a difficult pregnancy in which his mother invoked the intercession of Francis of Assisi.

1719 (aged seventeen) that made him vow that he would consecrate himself to God and join the Order of Friars Minor Capuchin if he managed to recover from it.

[4] Peis spent his time in a number of different occupations and was later appointed as the quester of alms due to his humble and modest conduct.

He had good relations with the people in Cagliari who realized that although he was begging alms he was also giving back to them in a spiritual manner.

[3] He would also instruct the children and the uneducated that he came across, and went out to comfort the sick and urge sinners to be converted and to perform penance.

[6] The cause for canonization opened after his death in 1844 (local level) and there were numerous reports of miracles attributed to him occurring at his tomb.

[3] The cause commenced and investigated the life and works of the late friar (a Positio was sent to the Congregation for Rites in 1868)[2] while the confirmation of his heroic virtue enabled Pope Pius IX - on 26 May 1869 - to title Peis as Venerable.

The confirmation of two miracles attributed to him (occurring after death) enabled Pope Pius XII to preside over his beatification on 16 June 1940.

The ratification of an additional two miracles (occurring after beatification) allowed for Pius XII to canonize the friar on 21 October 1951 in Saint Peter's Basilica.

The Positio dossier compiled during the cause noted that there were 121 miracles attributed to Peis during his life with an additional 86 reported after his death.