Tuscan is the official language of Italy, San Marino and Switzerland. It is the real name of what is commonly known as Italian. In the Italic Peninsula many dialects of Latin appeared and the Tuscan dialect spoken in Florence became the official language of the whole Italian territory.
Unfortunately, due to the European nationalism it started to be called "Italian".
Ezekiel: Hey, Luca, I've been told that your grandpa is Italian.
Luca: Hehe, yes. Did my father tell you about it?
Ezekiel: Yes, he did.
Luca: Well, you now know why I have been christened with a Tuscan name.