The Legione Redenta was an Italian military formation that participated in the Siberian Intervention during the Russian Civil War. It was formed with 2500 prisoners of war who had been captured by the Russians from the Austro-Hungarian Army.
The Legion fought against Bolshevik forces in Siberia and Manchuria, and was instrumental in protecting the Transiberian Railway necessary for the Allied support to the White forces.
With the Russian withdrawal from the war in 1918, German and Austro-Hungarian prisoners were allowed to return home as a result of the Brest-Litovsk treaty. Many of the Austro-Hungarian prisoners were of various nationalities reflecting the multi-ethnic composition of the empire.
A number of these prisoners were of Italian ethnicity, primarily from Trentino, Istria and Dalmatia (Italian nationalists considered these areas part of the Italia irredenta). The Italian government decided to form units from these prisoners (even because many of them declared to be Italian irredentists). They were allowed to fight for Italy and swore an oath to the King of Italy.
They were placed in a special new military unit called "Legione Redenta": this name was related to the word "redenta" (Italian for "redeemed") as a reference to the fact that the soldiers were "redeemed" from Austrian control and now were Italian legionaries.
As a result, the "Legione Redenta" was created in the summer of 1918 in China and attached to the "Corpo di Spedizione Italiano in Estremo Oriente" (Italian Expedition in the Far East). Initially they were stationed in the Italian Concession in Tientsin. They were trained in Tientsin by Major Cosma Manera, an official of the Italian Carabinieri who chose the name "Redenta" for the unit.