How did the language of The Divine Comedy differ from other philosophical works of the Middle Ages? What effect did Dante's decision to write his poem in Italian have?

During the Middle Ages, almost all philosophers used to write in Latin - the language of educated and elite class while as Dante wrote his best poem Divine Comedy in vernacular, Italian language-the language of common people.

Dante's decision to write in Italian had a long lasting impact on Italian language. It paved the way for Italian to emerge as a language respect across the European landscape. There were more innovations in this language and more and more people began to write in Italian and ultimately Italian became a cultured and literary language. It is due to the impact of his writing in Italian, he is being called father of modern Italian language.