quitter v partir

Interesting question, Jane!

Just to correct you, if you were to use the verb 'partir de', you would not use the article 'la'. ( il est parti de Corse) 

There is a difference in meaning between 'quitter un pays', which is more final, and 'partir d'un pays', which implies a temporary departure.

In this case, as Napoleon only returned to Corsica six times, the use of 'il a quitté la Corse' is correct.

Bonne continuation!