
The building was originally constructed by the Count of Eguía in 1548 as a castle-fortress. In those times, the Count of Eguía owned a 1,000 hectare estate on the banks of the Ebro, occupying a spot which until 36 years previously had been the frontier between the Kingdoms of Castile and Navarra. Since the Kingdom of Navarra had so recently been annexed to the Crown of Castile and Aragón, there was still fierce hostility between the Navarran and Castilian nobles, and Eguía was often harassed by the military forces which crossed the river Ebro via the ford at Alcanadre.