Klephts (Greek: κλέφτης, pl. κλέφτες - kleftis, kleftes, which originally meant just "brigand") were self-appointed armatoloi, anti-Ottoman insurgents, and warlike mountain-folk who lived in the countryside when Greece and Cyprus were a part of the Ottoman Empire. They were the descendants of Greeks who retreated into the mountains during the fifteenth century in order to avoid Ottoman oppression. They carried on a continuous war against Ottoman rule and remained active as brigands until the nineteenth century.
After the fall of Constantinople in 1453 and then Mistra in the Despotate of the Morea, the majority of the plains of Greece fell entirely into the hands of the Ottoman Empire. The only territories that did not fall under Ottoman rule were the mountain ranges (populated by Greeks and inaccessible to the Ottoman Turks), as well as a handful of islands and coastal possessions under the control of Venice. This situation lasted until at least 1821 (although there were some parts of Greece, such as Macedonia and Epirus, that still remained in Turkish hands until the 20th century) and this period of time in Greece is known as the Τουρκοκρατία or "Turkocracy."
Ottoman lands were divided up into pashaliks, also called eyalets; in the case of the lands that form modern Greece, these were Morea and Roumelia. Pashaliks were further sub-divided into sanjaks which were often divided into feudal chifliks (Turkish çiftlik (farm), Greek τσιφλίκι tsifliki). Any surviving Greek troops, whether regular Byzantine forces, local militia, or mercenaries had either to join the Ottoman army as janissaries, serve in the private army of a local Ottoman notable, or fend for themselves. Many Greeks wishing to preserve their Greek identity, Orthodox Christian religion, and independence chose the difficult but liberated life of a bandit. These bandit groups soon found their ranks swelled with impoverished and/or adventurous peasants, societal outcasts, and escaped criminals.
Klephts under Ottoman rule were generally men who were fleeing vendettas or taxes, debts and reprisals from Ottoman officials. They raided travelers and isolated settlements and lived in the rugged mountains and back country. Most klephtic bands participated in some form in the Greek War of Independence. During the Greek War of Independence, the klephts, along with the armatoloi, 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".
Klephtic songs (Greek: Κλέφτικα τραγούδια), or ballads, are part of the Greek folk music genre and are thematically oriented on the life of the klephts. They are especially popular in Epirus and the Peloponnese. Dvořák, the Czech composer, wrote a song cycle named Three Modern Greek Poems: the first one is entitled "Koljas - Klepht Song" and tells the story of Koljas, the klepht who killed the famous Ali Pasha.
The famous Greek dish klephtiko (or kleftiko), a dish entailing slow-cooked lamb (or other meat), can be translated "in style of the klephts". The klephts, not having flocks of their own, would steal lambs or goats and cook the meat in a sealed pit to avoid the smoke being seen.
Famous klephts 
- Athanasios Diakos
- Geórgios Karaïskákis
- Markos Botsaris
- Nikitas Stamatelopoulos
- Dimitrios Makris
- Odysseas Androutsos
- Theodoros Kolokotronis
- Antonis Katsantonis
See also 
- Dontas 1966, p. 24: "Born in 1800, Demetrios Makris, a kleftis, had succeeded his father to the kapetaniliki in the district of Zyghos. A simple yet very stubborn man, like Dimo - Tselios he was a great patriot."
- Encyclopaedia Britannica, Inc 1995, p. 564: "Other Greeks, taking to the mountains, became unofficial, self-appointed armatoles and were known as klephts (from the Greek kleptes, "brigand")."
- Sowards 1989, p. 75: "Greek irregulars had operated as bandit klephts and anti-Ottoman insurgents since before the Greek War of Independence in the 1820s."
- Cavendish 2009, p. 1478: "The klephts were descendants of Greeks who fled into the mountains to avoid the Turks in the fifteenth century and who remained active as brigands into the nineteenth century."
- Encyclopedia Americana 1919, p. 472: "KLEPTHS, klēfts (Greek, "thieves"). Greek bandits who, after the conquest of Greece by the Turks in the 15th century, kept themselves free in the mountains of northern Greece and Macedonia, and carried on a perpetual war against Turkish rule, considering everything belonging to a Turk a lawful prize."
- Encyclopedia Americana 1919, "KLEPTOMANIA", p. 472.
- Newer and Modern History (Ιστορία Νεότερη και Σύγχρονη), Vas. Sfyroeras, Schoolbook for Triti Gymnasiou, 6th edition, Athens 1996, p. 122
- Cavendish, Marshall (2009). World and Its Peoples. Marshall Cavendish. ISBN 0-7614-7902-3.
- Encyclopedia Americana. The Encyclopedia Americana: A Library of Universal Knowledge, Volume 16. New York and Chicago: Encyclopedia Americana Corporation.
- Encyclopaedia Britannica, Inc (1995). The New Encyclopaedia Britannica, Volume 1. Encyclopaedia Britannica. ISBN 0-85229-605-3.
- Dontas, Domna N. (1966). The Last Phase of the War of Independence in Western Greece (December 1827 to May 1829). Institute for Balkan Studies.
- Sowards, Steven W. (1989). Austria's Policy of Macedonian Reform. East European Monographs. ISBN 0-88033-157-7.