The Renaissance began in Italy due to its central location between Western Europe and the Muslim world, which led to increased trade and the growth of powerful city-states like Florence, Milan and Venice. These city-states used their wealth to promote the arts and ideas of the Renaissance, with Florence seen as its birthplace. Two key features of the Renaissance were a focus on classical works from ancient Greece and Rome, and the philosophical idea of humanism which emphasized the importance of individual people. Renaissance art developed the technique of realism to make images look more realistic through techniques like shading, perspective, and accurate human anatomy.