Ruy Diaz de Mendoza was a "caballero muy principal" of Granada. His historical importance is primarily due to his relationships with famous people of the 16th century. He was a relative of the Marques de Mondejar and married to Do a Catalina de Salazar, the daughter of Factor of New Spain Gonzalo Salazar. His granddaughter Do a Madalena de Mendoza financed the conquest of New Mexico. His grandsons Vicente Zaldivar and Juan Zaldivar were granted important military positions by their uncle Adelantado Juan de O ate. His ancestry has long been a mystery. Researcher Levi Villarreal, a many time descendant, takes the reader on a journey to uncover the origins of Ruy Diaz de Mendoza.