Santa Gadea is the name of a church in Burgos, Spain. The church is famous in history and literature for being the site where Rodrigo Díaz de Vivar (El Cid) at the behest of the Castillian Cortes, forced Alfonso VI to swear an oath that he was not an accomplice in the death of his brother, Sancho while he was besieging Zamora. Es el de la jura de Santa Gadea [1] is the most notable Spanish medieval romance about this event.