The Internal Revolutionary Organization (IRO) was a liberal nationalist revolutionary group in Bulgaria which was active from 1869 to 1872, led by the nationalist priest and teacher Vasil Levski. Headquartered at Lovech, the IRO was divided into regional committees which worked towards the goal of liberating Bulgaria from the Ottomans through a nationwide revolution, the establishment of a democratic republic, and the implementation of ethnic and religious equality. In 1872, Levski was captured and executed by the Ottoman authorities, and the organization's members joined other Bulgarian nationalist groups after Levski's death. Its goals and fundamentals later guided the IMRO organization of the early 20th century.