Tagma (military) in the context of "Special forces"

The Battle of Manzikert or Malazgirt was fought between the Byzantine Empire and the Seljuk Empire on 26 August 1071 near Manzikert, Iberia (modern Malazgirt in Muş Province, Turkey). The decisive defeat of the Byzantine army and the capture of the emperor Romanos IV Diogenes played an important role in undermining Byzantine authority in Anatolia and Armenia, and allowed for the gradual Turkification of Anatolia. Many Turks, travelling westward during the 11th century, saw the victory at Manzikert as an entrance to Asia Minor.

The brunt of the battle was borne by the Byzantine army's professional soldiers from the eastern and western tagmata, as large numbers of mercenaries and Anatolian levies fled early and survived the battle. The fallout from Manzikert was disastrous for the Byzantines, resulting in civil conflicts and an economic crisis that severely weakened the Byzantine Empire's ability to defend its borders adequately. This led to the mass movement of Turks into central Anatolia – by 1080, an area of 78,000 square kilometres (30,000 sq mi) had been gained by the Seljuk Turks. It took three decades of internal strife before Alexius I (1081–1118) restored stability to Byzantium. Historian Thomas Asbridge says: "In 1071, the Seljuqs crushed an imperial army at the Battle of Manzikert (in eastern Asia Minor), and though historians no longer consider this to have been an utterly cataclysmic reversal for the Greeks, it still was a stinging setback." It was the only time a Byzantine emperor became the prisoner of a Muslim commander, and the first time since Valerian that a Roman emperor was captured alive by an enemy force.

The Droungarios of the Watch (Medieval Greek: δρουγγάριος τῆς βίγλης/βίγλας, romanized: droungarios tēs viglēs/viglas), sometimes anglicized as Drungary of the Watch, was originally a senior Byzantine military post. Attested since the late 8th century, the droungarios commanded the Vigla or "Watch", one of the elite professional cavalry regiments (tagmata) of the middle Byzantine period, and was in charge of the Byzantine emperor's personal security. From c. 1030, the office was disassociated from its military origin and was transformed into a senior judicial position, thereafter usually referred to as the Grand Droungarios of the Watch (μέγας δρουγγάριος τῆς βίγλης/βίγλας, megas droungarios tēs viglēs/viglas). The office continued to exist as a mostly honorific court dignity in the Palaiologan era, until the very end of the Byzantine Empire in the mid-15th century.