Answer:
During the Italian reinansane period, Italy opened up its door for the people all across the world to come in and share their culture. This made many creative and intellectual mind gathered in various Italian cities (most notably Florence and Rome) to study about art, religion, history, and philosophy.
Even though they have a lot of adversity, people who leave in these Italian cities were considered very progressive at that time. Even to the pointes where the churches referred to them as heretics.
As these people interact with one another, cultural exchanges occurred between them. When they came back to their home country, they will spread the culture even more for the locals to hear. This created a multiplying effect that accelerate the spread of culture.