As a nation state, Italy has emerged only in 1871. Until then the country was politically divided into a large number of independant cities, provinces and islands. The currently available evidences point out to a dominant Etruscan, Greek and Roman cultural influence on today's Italians.
I am researching a Louis Bertolotto born 1800 Genova, his Father is supposed to have been a French Navy Captain called John Bertolotto. He reached London by around 1830 and then moved on to Canda in 1850
I discovered on the following site some detail about the Waldensians and a mention that the Bertolotto name was a common Waldensian one.