He was posthumously promoted to Field Marshal in April 1809 and made a Commander of the First Battalion of the Spanish Royal Guards Regiment in May 1810. In 1815 a black marble tablet was placed on his grave which stated that Álvarez had been poisoned, and was a "Victim of the Iniquity of the French Tyrant". In December 1823 French troops, ironically invading Spain in order to restore the tottering throne of Ferdinand VII, passed through Figueres, and on the orders of Marshal Moncey, formerly Napoleon's Inspector-General of Police, destroyed the plaque.