Isabella d'Este (1474-1539), daughter of the Este dukes of Ferrara and wife of Marchese Francesco II Gonzaga of Mantua, co-regent of the Gonzaga state, art collector, musician, diplomat, dynastic mother, traveler, reader, gardener, fashion innovator, and consummate politician, was also, as this volume attests, a prolific letter writer with a highly developed epistolary network. Presented here for the first time in any language is a representative selection from over 16,000 letters sent by Isabella to addressees across a wide social spectrum. Together, they paint a nuanced and colorful portrait of a brilliant and influential female protagonist of early modern European society.