Pierre-Auguste Renoir (1841–1919) is so closely associated with Impressionist painting that the surprising diversity of his early work is frequently forgotten. His most important model during these early years was the artist’s mistress, Lise Tréhot, with whom he had a relationship between 1865 and 1872. After posing for a large group of prominent early works, including Woman in a Garden and En été (both 1868), Lise turned her back on the Bohemian lifestyle in favor of a bourgeois marriage. The paintings created between 1864 and the end of the following decade show the broad spectrum of Renoir’s art and the development of his artistic vocabulary, including the Impressionist phase. This is the first extensive examination of the painter’s early oeuvre and the strong influence of his close friendships with other artists, such as Éd0uard Manet, Claude Monet, Frédéric Bazille, and Alfred Sisley.