Armatoloi (pronounced ar-ma-to-LEE), (Greek plural Αρματολοί; singular Armatolos - Αρματολός; also called Armatoles in English) were Greek Christian irregular soldiers, or militia, commissioned by the Ottomans to enforce the Sultan's authority within an administrative district called an Armatoliki (Greek singular Αρματολίκι; plural Armatolikia - Αρματολίκια). Armatolikia were created in areas of Greece that had high levels of brigandage, or in regions that were difficult for Ottoman authorities to govern due to the inaccessible terrain, such as the Agrafa mountains of Thessaly, where the first armatoliki was established in the mid-15th century.
An armatoliki was usually commanded by a kapetanios (captain), often a former klepht captain who had been hired by the governing Ottoman Pasha to combat, or at least contain, brigand groups in the region. In most cases, the captain would have gained a level of notoriety as a klepht to force the Ottomans to give him the amnesty and privilege that came with an armatoliki. Therefore, it was not surprising that armatolos units were organised in very much the same way as the klephts, with a captain assisted by a lieutenant called a protopalikaro, who was usually a kinsman, and the remaining force made up of armatoloi.
Over time, the roles of the armatoloi and klephtes became blurred, with both reversing their roles and allegiances as the situation demanded, all the while maintaining the delicate status-quo with the Ottoman authorities. Many captains ran their armatoliki like their personal fiefdoms, exacting a heavy toll of extortion and violence on the local peasantry.
During the Greek War of Independence, the armatoloi, along with the klephtes, formed the nucleus of the Greek fighting forces, and played a prominent part throughout its duration.
The word first appeared during the 15th century during Venetian times. It is derived from a medieval loan from Latin arma ('weapon'), probably via Greek αρματολόγος ('someone who deals with arms', 'an armed person') > αρματολόος > αρματολός. According to an older hypothesis, the development of the word may also have been influenced by a conflation with the similar-sounding αμαρτωλός ('sinner'), which may have been associated with the topic of armed bands through phrases such as "αμαρτωλοί/αρματολοί και κλέφτες" (meaning 'sinners and thieves', but also 'armatoloi and klephts'). Owing to the parallelism with "αμαρτωλός", the word was also sometimes spelled as "αρματωλός", with the letter omega.
According to Vacalopoulos, the armatoles first appeared as an institution in Agrafa (Thessaly) during the reign of Murad II (1421–1451). From there, they spread to other parts of Greece except the Peloponnese.
Ottoman period 
The armatoloi were organized based on a feudal system under which military/police units maintained their duties in exchange for titles of land. When the Ottomans conquered the plains of Greece (along with a myriad of islands), they did not disband or remove the armatoloi. In fact, the Ottomans established treaties with the armatoloi in order for them to maintain their military/police functions. The Ottomans would have units of armatoloi or kapetanioi (καπετάνιοι; captains) function as peace-keepers in territories near difficult terrain (i.e. mountain passes) or in areas where resistance to foreign rule entailed acts of theft by the klephts.
The armatoloi were mostly concentrated in Macedonia, Thessaly, Epirus, Acarnania, and Aetolia (specifically Agrafa). In the Peloponnesus, armatolismos did not develop in the same manner as it did in Roumeli and Epirus. In the Peloponnesus, the kapoi (κάποι) and the meintanides (μεϊντάνηδες) were similar to the armatoloi. If in certain regions, the institution of armatolismos was not implemented, the territories were divided into armatolikia (αρματολίκια) or protakta (προτάκτα). These territories extended from Axios river (Αξιός) to Ambracian Gulf (Αμβρακικός) and up to the Corinthian gulf (Κορινθιακός). The kapetanioi would often have authority over these territories via inheritance/succession. A single kapetanio was at first forced to submit his authority to the pasha who controlled the periphery. Later, all kapetanioi were forced to submit to Dervedji pasha (Δερβετζή πασά).
During the 18th century, there were around seventeen armatolikia. Ten of them were located in Thessaly and the eastern regions of Central Greece, four of them in Epirus, Acarnania, and Aetolia, and three in Macedonia. Every kapetanio had his palikaria (παλικάρια). Among these palikaria, the best recognized leader, secretary, and sometimes successor of the kapetanio was deemed protopalikaro (πρωτοπαλίκαρο). The palikaria would train with their weapons on a daily basis.
The main weapon the palikaria utilized was the kariofili (καριοφίλι). Marksmanship was the proverbial hallmark that defined the palikaria. They were also capable in the art of ambushing and mobility. The palikaria were resilient toward thirst, hunger and even the painful difficulties in their encounters with the klephts.
The term klephtopolemos (κλεφτοπόλεμος) was used to name the strategies/tactics that both the klephts and armatoloi utilized. These tactics are used today for unconventional military campaigns by small guerrilla groups. The armatoloi would conduct campaigns during nighttime. This strategy was known as "going out to pagana" (έβγαιναν στην παγάνα). The armatoloi would usually do this when the klephts were coming out of their dens. The armatoloi would defend themselves in improvised forts (called meterizia; μετερίζια) against the guerrilla tactics utilized by the klephts (specifically known as klephtouria; κλεφτουριά). A general offensive campaign by the armatoloi was known as giourousi (γιουρούσι). During one of these campaigns, the armatoloi would make effective use of swords and warcries.
Before 1821 
For the Ottomans, it became progressively more difficult for them to distinguish the armatoloi from the klephts. Both groups began to establish relations with one another under a common ethnic rubric. This collaboration was also based on mutual sentiments against foreign conquerors. Since both groups were armed and possessed military experience, they helped Greeks become better warriors before the advent of the Greek Revolution of 1821.
The first recorded appearance of collaborations between armatoloi and klephts goes back to 1585 during the wars fought between the Venetians and the Ottomans. During this time, Theodoros Boua-Grivas incited an insurrection in Acarnania and Epirus with armatoloi Poulios Drakos and Malamos from Epirus. The Sublime Port continued to have trust in armed groups such as the armatoloi up until 1684. During that year, the bodyguards of the Port, the armatoloi, became carriers of ethnic-oriented ideas. Prominent armatoloi from the 17th century were Soumilas (Σουμίλας), Meintanis (Μεϊντάνης), Livinis (Λιβίνης), Kourmas (Κούρμας), the Balaorites (Βαλαωρίτες), etc. Though these individuals engaged in failed rebellions, their attempts became an inspiration for future armatoloi to follow.
Revolution of 1821 
Since the 1770s the Russian Empire tried to inspire a rebellion in Greece (see Orlov Revolt). During these attempts many armatoloi took up arms. With the outbreak of the Greek War of Independence, (an insurrection in which Russia had, for once, no involvement as an instigator or agitator) a number of prominent armatoloi abandoned any allegiance to the Ottoman state and formed the nucleus of the Greek land forces. Among them were Odysseas Androutsos, Georgios Karaiskakis, Athanasios Diakos, and Markos Botsaris. There were armatoloi (such as Karaiskakis) that were initially employed by Ali Pasha, and of whom some fought with him against the Ottomans. In 1820, when Ali declared his territory’s withdrawal from Ottoman influence, he depended heavily on the Greek armatoloi to help him. Though Ali’s insurrection failed, this bold experiment did not weaken the ability of the armatoloi to fight for independence and contribute to the Greek Revolution.
Famous Armatoloi 
- Newer and Modern History (Ιστορία Νεότερη και Σύγχρονη), Vas. Sfyroeras, Schoolbook for Triti Gymnasiou, 6th edition, Athens 1996, p. 122
- Babiniotis, G. (1998). Λεξικό Της Νέας Ελληνικής Γλώσσας. Athens.
- Vacalopoulos, p. 211. "The earliest origins of the armatoles are lost in the murk of history. However, in my Origins of the Greek Nation, an analysis of various sources not previously sifted in any thorough way suggested that the institution first appeared in Thessaly during the reign of Murad II (1421-1451), specifically in the Agrafa, Thessaly. From there, it subsequently spread to other parts of the Hellenic world, though not to the Peloponnese."
- Dakin, Douglas (1973). The Greek struggle for independence, 1821-1833. University of California Press. p. 232. ISBN 0-520-02342-0. "…the chiefs Dimitrios Makris…Makris, armatolos of Zigos, was one of the heroes of Mesolonghi. He had acquired much wealth by plundering the Turks of Vrachori, and he had done well for himself out of the proceeds of the English loans."
- A front-loading gun (From Cario & Figlio, an 18th century maker of such guns)
- Diamantopoulos, N., Kyriazopoulou, A., "Elliniki Istoria Ton Neoteron Hronon", OEDB, (1980).
- Brewer, David, "The Greek War of Independence", The Overlook Press (2001). ISBN 1-58567-172-X.
- Paroulakis, Peter H., "The Greeks: Their Struggle For Independence", Hellenic International Press (1984). ISBN 0-9590894-1-1.
- Stratiki, Poti, "To Athanato 1821", Stratikis Bros, (1990). ISBN 960-7261-50-X.
- Vacalopoulos, Apostolis. The Greek Nation, 1453-1669. Rutgers University Press, 1976.