During the English invasions of 1806 and 1807 he participated in the defense and reconquest Buenos Aires, serving as second lieutenant in the Escuadrón de Carabineros Carlos IV. He was promoted to lieutenant of the same battalion by its heroic action. In 1810 Galup, adheres to the May Revolution cause. That same year, he served under orders of the Colonel Ignacio Álvarez Thomas.