Some of those causes would be the Crusades, the Decline of Feudalism, the Rise of he Mongol Empire, and the Roles of Rulers, Nobles, Popes, and the Middle Class but the two most important causes are the Crusades and the Decline of Feudalism. During the Crusades, Crusaders brought in new thoughts and beliefs, which replaced the old thoughts and beliefs of other well known groups. They had also brought in new ideas and materials from other people in the Middle East such as scientific books of Aristotle, the Arabic numerals, mariners compass, and paper.
These were all brought into Europe and helped the hold of Christianity which was the starting point of the Renaissance. When it came to the Renaissance flourishing, it was only able to flourish because of the decline of Feudalism. The decline of Feudalism was when the middle class started to show support to the king. This started the promotion of the Renaissance which had then started the decline. Although it had many causes the Renaissance had many effects to it as well.
There were three types of effects; social effects, economic effects and political effects. Some social effects of the Renaissance were manners and etiquette, the development of literature and fine arts, and scientific inventions and discoveries. Economic effects were the development of trade and commerce and Colonialism. Lastly the political effects were the rise of strong monarchies and a change in warfare. All these effects of the Renaissance play their own part in their own category they were placed under.