"Squadriglia 91a" of the "Corpo Aeronautico Militare" was established on 1 May 1917, drawing upon the existing "70a Squadriglia" for its start. The new unit deployed to Istrana, near the ongoing Battles of the Isonzo, on 6 June 1917, with the objective of supporting ground action in the Trentino. It scored 14 victories within its first month of operations, largely because it included such experienced pilots as Francesco Baracca, Luigi Olivari, Ferruccio Ranza, and Fulco Ruffo di Calabria. Indeed, the "91a Squadriglia" gained the nickname "Squadriglia degli assi" (Squadron of the aces).