When Leonardo was about 17 he got an apprenticeship at the renowned workshop of Andrea del Verrochio in Florence where he learned and became aware of his artistic skills. In 1482 Leonardo moved from Florence to Milan where he entered the service of the Duke of Milan for 17 years as the court artist, architect and engineer. It was over the course of these years that Leonardo truly developed his creative and artistic genius. Da Vinci's "The Last Supper" was one such masterpiece completed in Milan. During this time the Duke had Leonardo devote himself to painting portraits, devising elaborate festivals and designing buildings. In addition, Leonardo engineered various war machines such as a triple barrel cannon which had an elevation adjusting mechanism by means of a peg blocking system. He engineered many different work machines throughout his life including a machine for making ropes, a drilling machine, an odometer and a deep-sea diving suit.

In 1499 the French took over Milan so Leonardo left the city searching for employment from place to place. Five years later he found himself back in Florence where he started work on the "Mona Lisa". Leonardo's ability to portray perspective is characteristic in all of his paintings. Not only did he employ the use of linear perspective in his paintings; in other words having a vanishing point with objects getting proportionally smaller the further they were from the foreground, but he also developed a new kind of perspective he called aerial perspective. He noticed that the further away mountains are, the closer they are in color to that of the sky. He was the first artist to make careful measurements of this phenomena and suggested rules to be followed when painting. This subject was called aerial perspective.