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-1400s.
An armatoliki was usually commanded by a kapetanios, 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 in order 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 a personal fiefdom, 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.
Yannis Makriyannis referred to the "klephtes and armatoloi" as the "yeast of liberty"..
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 Sterea Ellada, 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 guerilla 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.
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 famous individuals engaged in failed rebellions, their sacrifices became an inspiration for future armatoloi to follow.