Nassau on Horseback is a study of rulership image-making. Equestrian imagery used for this purpose has a tradition extending back more than two thousand years to the Greeks and Romans. Their rulers understood that authority is partly a matter of impressing and persuading those over whom authority is wielded through the public display of their images. Eventually rulers all over the world adopted this practice as is testified by ca. 900 equestrian rulership and memorial statues in 76 countries.00This dissertation aims to determine if and how this practice was adopted by the stadholders Hendrik III, William of Orange, Maurits, Frederik Hendrik, William III, and more recently by Queen Beatrix of the Netherlands. Since the early 16th century some 225 Orange-Nassau equestrian tapestries, paintings, prints, statues, photographs and a film have come down to us (not counting other works of art and memorabilia). It will be determined if these images evolved in accordance with the aristocratic tradition, or as result of a deliberate rulership communication strategy. Orange-Nassau equestrian imagery has not been studied before from this point of view.