The area today known as Croatia seems to have been invaded and controlled by huge empires over the past thousand years. The Venetians, the Ottomans, and then the Austrians. But instead of speaking Venetian, Turkish, or German, Croatia seemed to maintain the use of the Croatian language throughout. Why is this the case?
Croatia willingly joined those empires to prevent being conquered and were given certain rights because of the fact that they provided lots of high quality soldiers to the Austrians. And the Italians controlled mostly smaller villages and the land around them, not many croat cities because the Italians came their for natural resources like lumber. Kinda sad you can still see the effect, because the coast has no forests left. Croats were also independent from when they arrived around 320 AD all the way to 1250 AD and even then they were still sort of independent. They only became annexed around 1500 AD