How did the Italian renaissance happen?

Answer 1

One view:

What mainly caused the renaissance (which means rebirth in french) was the black plague. The black plague killed one third to one half of the people in Europe. It changed peoples perspective of things. It turned some even more towards religion and god. Other people began to hate god and question him. Others began to look more towards medicine and science. and so with people inquiring more into the wonders of the world, a great age of learing started changing the world.

Another view, not necessarily in disagreement:

I think the Renaissance began with the writings of Dante and Petrarch, and the artwork of Giotto di Bondone, before the plague hit. These people had profound effects on thinkers of their own times and later polymath geniuses like Alberti and da Vinci.

Petrarch, probably even more than Dante, was important as a founder of Humanism, a movement that put emphasis on social science, education in the humanities, and secular ideology, while rejecting superstition and religious dogma as a basis for morality and ethics.

Giotto's influence should not be underestimated. His development of linear perspective provided artwork that conformed more to the view of the real world as seen by the eye. In studying this to see how it was done, Renaissance thinkers were confronted by the novel idea of a "station point," the actual place or "point of view," from which a person sees the world, and this, I believe, had the great effect of making them see that a person's understanding of reality or "perspective" depended, to some degree, on his position, or "point of view."

The effects of such thinkers were profound, and stood in stark contrast to the people of the Middle Ages, who tended to be anonymous and not prone to self glorification. People of the Renaissance began to promote themselves and their own ideas, with the belief that they had intellectual licence to oppose the earlier thinkers to whom they compared themselves with some feeling of superiority.

The Condemnations of 1210-1277 made teaching that Aristotelian Science was true a heresy. This opened the door for ideas that did not conform to Aristotle, including both imported Islamic science, and home grown European developments, to advance. This improved understanding of physics, optics, chemistry, and some other areas of science

The importation of Arabic numerals, during the 13th century, provided an impetus to establish new schools that taught middle class children, boys and girls, the new arithmetic methods they enabled. These schools, called abacus schools, also taught reading and writing in the vernacular and were aimed specifically at preparing the children for lives in commerce. This must have had an effect on humanism.
The renaissance began with a cultural re-birthing from the 14th century to the middle of the 17th centuries. This was mostly in Italy.

Answer 2

One major factor was the reintroduction of Greek science and philosophy to continental Europe by the Muslims.

Answer 3

Chuck Norris made it happen

Answer 4

1300's to late 1500's