Cases of Italian embedded self-portraiture appear in the sacred art of some of the most renowned artists of the Cinquecento and early Seicento, artists such as Bronzino, Michelangelo, Titian, Tintoretto, and Caravaggio. This thesis first examines the history of the practice from its origins in Quattrocento Florence and Venice then argues that an important development in the function and presentation of embedded self-portraits can be observed as Cinquecento artists experienced broad shifts in religious and cultural life as a result of the Reformation and Counter-Reformation. It also assesses three works by Caravaggio to suggest that embedding self-portraits in religious art was a variable and meaningful convention that allowed artists to inject both their personal and public emotions. This thesis argues that in the Cinquecento and early Seicento, the very gesture of embedding a self-portrait in sacred artworks provided a window into an artist's individuality, personality, and piety.