We live in a time in which photographs have become extraordinarily mobile. They can be exchanged and circulated at the swipe of a finger across a screen. The digital photographic image appears and disappears with a mere gesture of the hand. Yet, this book argues that this mobility of the image was merely accelerated by digital media and telecommunications. Photographs, from the moment of their invention, set images loose by making them portable, reproducible, projectable, reduced in size and multiplied. The fact that we do not associate analogue photography with such mobility has much to do with the limitations of existing histories and theories of photography, which have tended to view photographic mobility as either an incidental characteristic or a fault.