El juramento de las Cortes de Cádiz de 1810 (Oath of the Cortes of Cadiz in 1810) by José Casado del Alisal (18321886). When the Cortes convened in Cádiz in 1810, there appeared to be two possibilities for Spain's political future if the French could be driven out. The first written Spanish constitution was promulgated in Cádiz on 19 March 1812. The Constitution of 1812 is regarded as the founding document of liberalism in Spain.