For his performance in his career, with the entry of Brazil into World War I, he was appointed in October 1917 to attend the preparatory military mission which the Brazilian Army sent to France to fought the Western Front. There, he spent a brief internship at Saint-Cyr to learn about the adaptation of his military branch (the Cavalry) to the then-recent invention, the tank. After this, he joined the 4th Dragoons Regiment of the 2nd Cavalry French Division. That year, this regiment (as other French cavalry units) using Schneider and St Chamond models, at the cost of heavy losses, participated actively in the containment of German spring offensives, and later, already with the then new and revolutionary Renault FTs, in the successful final Allied counter-offensives.