The monumental heart of this district is the Palazzo Pitti, a massive stone fortress of a palace that spans 32,000 square meters. Its history is a fascinating story of Renaissance rivalry. It was commissioned in 1458 by the ambitious banker Luca Pitti, who reportedly wanted his windows to be as large as the main doors of the rival Medici family's palace across the river. Ironically, the Pitti family eventually went bankrupt trying to finish this grand dream, and the palace was purchased in 1549 by Eleonora di Toledo, the wife of Grand Duke Cosimo the First de' Medici. It then became the primary royal residence for the Medici dynasty, the House of Lorraine, and even the Kings of Italy when Florence was briefly the nation's capital between 1865 and 1871. Today, the palace houses several elite museums, but the real secret is the Boboli Gardens out back—an open-air masterpiece of landscaping that served as the prototype for royal gardens all across Europe.