The idea of the Renaissance spread from Italy to the North European countries. Factors such as expanded trade, the growth and development of European cities, the invention of the printing press, the rising rich class who wanted to support art, contributed to this. Many kings experienced artistic achievements as a source of national pride. Also, artists fled the war in Italy in the late 1400's. The Catholic Church's lack of interest in participating in the real life of people played a major role, simply did not want the change.
Still, the main factor was trade and technological innovation that go together.
The invention of the printing press is the dominant factor. Around 1450. Johannes Gutenberg invented mobile printing press.