Turcomans, or Türkmen, was the name given principally to the Oghuz (Ghuzz) Turks when they entered the Islamic world from their homeland to the northeast of the Caspian Sea in the course of the eleventh century.
The term is most likely to mean “the Turks,” and to have been used for Turkish immigrants who had accepted Islam. The Turks in question were those who had accompanied the Saljûq clan of the Oghuz into Persia from the beginning of the eleventh century. As unarmored horsemen armed with composite bows and curved swords, they provided the Saljûqs with the numbers to conquer an empire, but as sheepherding nomads, they moved through the mountains to the south of the Caspian Sea in search of pasture, resisting Saljûq control as they pressed ahead into Mesopotamia, Anatolia, and Syria as ghazis (warriors for Islam) to create their own principalities. They failed at Damascus and Jerusalem, but the Dānishmendid dynasty and others established themselves in highland Anatolia, and the Artûqids in Diyar Bakr, becoming more heavily armed and armored in the Saljûq fashion.
The westward spread of these nomads across the uplands of northern Persia and Anatolia introduced a major new element into the population and the economy of the highland zone. In Anatolia (Asia Minor) it began the process of Turkification and Islamization of the majority of the population by the end of the Middle Ages, but whether this resulted from repopulation or conversion is difficult to say. Turcomans often made up an important element of the Muslim military forces that confronted the Franks of Outremer, serving not only their own leaders but frequently also joining armies led by Saljûq commanders. However, they were usually less amenable to discipline than the Saljûqs’ own household troops.
By the end of the twelfth century, the Turcoman principalities of Anatolia were in retreat before the Saljûq sultanate of Rûm and the Ayyûbids, but farther east the Turcomans of Khurasan had defeated the Great Saljûqs, before the whole region fell to the Khwārazm-Shāh and the Mongols. Turcoman expansion, however, continued, until by the end of Mongol rule in the fourteenth century, a rash of new Turcoman principalities appeared in Anatolia, notably the Ottomans, the Aydin dynasty at Izmir (Smyrna), and the Karaman at Konya (Ikonion). By the fifteenth century, the Turcoman Kara Koyunlu (“Black Sheep”) in eastern Anatolia, followed by the Ak Koyunlu (“White Sheep”) in Diyar Bakr, had conquered a vast but ephemeral empire in Iraq and Persia. All fell victim to the Ottomans and the Safawids of Persia.