Premise: General Francisco Javier Castaños Aragorri Urioste y Olavide, Count of Castaños y Aragones, 1st Duke of Baylen (es: "Don Francisco Javier Castaños Aragorri Urioste y Olavide, Conde de Castaños y Aragones, primer Duque de Bailén."; 22 April 1758 – 24 September 1852), was a Spanish general during the Peninsular War.
Hypothesis: General Francisco Javier Castaños Aragorri Urioste y Olavide was his father's eldest son.