In European history, the period between the 400s and 1400s is known as the Middle Ages. 
During this time, most art in Europe was dedicated to religious subjects and stories from the Bible. This was because, in the year 313, Emperor Constantine made Christianity the official religion of the empire. After that, churches were built all over Europe and rulers tried to build bigger and better churches and cathedrals than their predecessors. Churches were architectural masterpieces that contained lots of art such as paintings and murals.
Things changed during the 14th century when artists and scholars started questioning the role of religion in society and paid more attention to the human body, human achievement and the world around them. Scholars began studying the art and science of ancient Greece and Rome and humanism emerged and developed. All of this was reflected in the arts.
Humanism is a philosophy that places value on people rather than deities. It celebrates the human body and human accomplishment. In society, humanism allowed an acceptance of science and scientific experiments and methods. It increased interest in precise sciences such as mathematics. Starting in Italy, the Renaissance spread slowly across Europe for over 200 years.