Juan Vivion de Valera

It was alleged that Vivion de Valera, always in poor health, left his young family behind him and traveled to Colorado, hoping that perhaps the healthier air would help him out only to die within a few months. However, not merely is there no record of the wedding. No record exists of the existence of a "Juan Vivion de Valera" anywhere in the United States: no birth certificate, no baptismal certificate (if he was a Catholic), no wedding certificate and no death certificate. While it was possible that he was born abroad and so either had a foreign birth certificate or was not registered, the absence of a death certificate for someone stated definitely in Éamon de Valera's family history to have died in the United States has puzzled researchers. Some scholars have questioned whether he ever existed. There has been a suggestion that he was related to the French painter Achille Deveria as Éamon de Valera was known to be particularly fond of his works.

A memoir by a grandson, Terry de Valera, offers an account of the Hispanic origins of the family. Juan Vivion de Valera, son of Juan Manuel de Valera, was born in 1853 in Matanzas, Cuba where his family had apparently lived since 1827. Cuba was then regarded as a province of Spain (for this reason his nationality was officially "Spanish"). These de Valeras originated in Vizcaya in Spain; San Antonio de Valera was the name of the area they owned in the south of Matanzas province in Cuba.