What caused the Renaissance to arrive in Italy first?
Italians tended to be less religious than other Europeans, even during the Middle Ages.
Most of the books by the ancient philosophers had been stored in a library in Italy, so Italians were the first to rediscover them.
Italy had fertile soil, so it was easy for ideas to blossom there, like flowers.
Italy had a lot of port cities, so new ideas sailed in from all over the world.