Internal Revolutionary Organization

The Internal Revolutionary Organisation (IRO; Bulgarian: Вътрешна революционна организация (ВРО), romanized: Vatreshna revolyutsionna organizatsia (VRO)) was a Bulgarian revolutionary organisation founded and built up by Bulgarian revolutionary Vasil Levski between 1869 and 1871. The organisation represented a network of regional revolutionary committees which were governed by a Central Committee in the town of Lovech.

Source: Wikipedia — Internal Revolutionary Organization (CC BY-SA 4.0)