The document provides background information on key figures and developments during the High Renaissance period in 16th century Italy. It discusses the three major figures of the High Renaissance - Leonardo da Vinci, Raphael, and Michelangelo. For Leonardo, it describes his training in Florence and career working for patrons in Milan and Florence. It highlights his use of sfumato technique and imaginative landscapes. The document also provides analysis of Leonardo's famous works like the Mona Lisa, noting its pyramidal composition and enigmatic smile.