Look at these names : Roberto Baggio, Roberto Muzzi, Roberto Di Matteo. From those names i can tell that their family name is Roberto. The same goes for Allesandro Del Piero, Allesandro Nesta and Allesandro Costacurta.
Problem happen with this sibling : Fillipo Inzaghi and Simone Inzaghi. What is their family name? I mean.. i never found any Inzaghis except them. So i assumed that the family name is Fillipo as i have seen it before (Fillipo Galli, Fillipo Maniero) then problem come, if the older is Fillipo why the younger is Simone? This is confusing 馃樀馃樀
@YukikoAmagi So, 1st Roberto is not the family name, it's the first name. I think you're aware of that but you just made a mistake here. The family name of Inzaghi is Inzaghi LOL, Filippo etc are first names.
LOL if you knew a bit of Italian I'm sure you'd have fun with the website NOMIX who's completely dedicated to names and surnames, with funny features like this one. This is the map of the Inzaghi families in Italia :-P