Discourses on photography attribute several functions to the medium, including artistic self-expression, documentation, experimentation, illustration, and the preservation of memory. This latter function, however, is discussed less frequently and appears even less often in public discourse, although in modern art history the relationship between photography and memory plays a decisive role in shaping both the creation of images and their afterlife. The photographs preserved in family albums help safeguard the memories of individual lives, while archival image material can bring entire historical periods to light. What accounts for the particularly close relationship between photography and memory? Can photography’s memory-preserving function survive in the age of digitization? What conditions transform an image into a mnemonic object, and what happens when these conditions cease to exist?