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 can only guess that some Irish came to Italy for the same reason that tens of thousands (?) came to the US - because of the diseased potato crops and the famine which ensued.
An Italian novel for kids called "La Freccia Azzurra" (The Blue Arrow) says that all the children in the world wait for Christmas Eve to get presents from Santa Clause, but Italian kids are the luckiest in the world because they get presents again on the 6th of January by the Befana. Who is the Befa...