Bulgarian Volunteer Corps

The Bulgarian Volunteer Corps (Bulgarian: Българско опълчение, romanized: Bŭlgarsko opŭlchenie, lit. 'Bulgarian militia', Russian: Болгарское ополчение, romanized: Bolgarskoye opolcheniye), which the members known as the Opalchentsi (Bulgarian: опълченци), were Bulgarian voluntary army units, who took part in the Russo-Turkish War of 1877–1878. The people in these units were called opalchenets-pobornik (опълченец-поборник) roughly meaning "folk-" or "regiment-combatant".

Source: Wikipedia — Bulgarian Volunteer Corps (CC BY-SA 4.0)