Kammala jumla mai zuwa: Alava ya yi aiki a matsayin mataimakin mai kula da rundunar sojan ruwa a lokacin kawancen Spain da Faransa amma ya sauya bangarori a 1808 lokacin da Napoleon
sun mamaye Spain. Cortes na Mutanen Espanya sun nada shi kwamishina (matsayin soja) a hedkwatar Sojojin Burtaniya, kuma Duke na Wellington, wanda ya ɗauke shi da babban tagomashi, ya mai da shi ɗaya daga cikin mataimakansa na sansanin. Kafin karshen yakin ya tashi zuwa matsayin brigadier-general. Daga baya ya shiga hedkwatar Sojojin Peninsular na Burtaniya a matsayin mai ba da shawara na soja kuma ya zama babban abokin Duke na Wellington. A lokacin yakin Waterloo a 1815, Alava shi ne jakadan Mutanen Espanya a Hague a kotun Sarki William I na Netherlands, wanda ya ba shi damar halartar Duchess na Richmond ball kuma ya kasance a gefen Wellington a lokacin yakin Waterloo.