He was born in 1900 in Padova where he studied theology as a Jesuit priest.
In 1922 he moved to Albania as a missionary and actively participated in magazines such as Lajmetari i Zemres s'Jezu Krishtit, and Leka, which he directed since 1932.
During World War II he became a professor of the Albanian language in the University of Palermo.
[1] Valentini is the author of several important works on Albanian history, law, numismatics, and sacred art.
[1] In 1940 Valentini was one of the founders and general secretary of the Royal Institute of the Albanian Studies, the predecessor institute of the Academy of Sciences of Albania.