Columbus Italian? Could be. He was born in town Calvi on island Corse (Corsica). If you ask people living there if they are Italian, the answer will be no. Same if you ask if they are French.

But in the past Italian families from Tuscany had very strong influence and strong holds on Corsica, so at the end of story he could /was an Italian guy.

This is not really important. We all now that Vikings and Celts were there first!