The Palace rises over a low hill facing what were the ancient city walls of Tafalla. Part of the Mencos family, then living near the Church of Saint Mary, purchased a plot of land “extramuros” on this hillock, around 1590. It is here, on the royal path that leads to Olite, that their new residence was built.
It remained the main Mencos family’s main dwelling until 1770. The home of the Real Defensa, on Zapatería Street in Pamplona, became the main residence of the Mencos family following the marriage of Joaquín José Mencos y Areizaga (Conde de Guendulain and Barón de Bigüezal, Gobernador de los Reales Alcázares of Tafalla) to Magdalena Eslava y Eslava, (Marquesa de la Real Defensa y Condesa del Fresno de la Fuente). Until the mid twentieth century, the Palace in Tafalla became a secondary residence, it has since returned to being the main home of the entailed estate of the Mencos of Tafalla.
The Palace was occupied by different troops on numerous occasions during the various confrontations that took place in the region. An example of such occupations was that of the French Army between 1808 and 1813 during the Spanish War of Independence (or Peninsular War). The same fate befell it during the First Carlist War, becoming the headquarters of the army of Maria Christina between 1833 and 1839. In the Third Carlist War (1873 -1876), it became a Red Cross Hospital (it would appear to be the first hospital of what were then called Aid Societies for the Nursing of the War Wounded, established on a frontline). In the twentieth century, during the Spanish Civil War, it was occupied once again in 1936, becoming a training academy for under-officers and the Headquarters of the Civil Guard. The building suffered significantly over the centuries. Renovation work started in the 1940s, with the impulse of Don Tiburcio Mencos y Bernaldo de Quirós, Marqués de la Real Defensa and is currently in a far better state than it was before the Civil War.