Middle Byzantine army (641–1081 AD) was the army of the Byzantine state in its classical form (i.e. after the permanent loss of its Near Eastern and North African territories to the Arab conquests after 641 AD). This army was largely composed of semi-professional troops (soldier-farmers) based on the themata military provinces, supplemented by a small core of professional regiments known as the tagmata. Ibn al-Fakih estimated the strength of the themata forces in the East c. 902 at 85,000 and Kodama c. 930 at 70,000. This structure pertained when the empire was on the defensive, in the 10th century the empire was increasingly involved in territorial expansion, and the themata troops became progressively more irrelevant, being gradually replaced by 'provincial tagmata' units and an increased use of mercenaries. Komnenian Byzantine army (1081–1204) The Komnenian Byzantine army was named after the Komnenos dynasty, which ruled from 1081 to 1185. This was an army built virtually from scratch after the permanent loss of half of Byzantium's traditional main recruiting ground of Anatolia to the Turks following the Battle of Manzikert in 1071, and the destruction of the last regiments of the old army in the wars against the Normans in the early 1080s. It survived until the fall of Constantinople to the Western crusaders in 1204. This army had a large number of mercenary regiments composed of troops of foreign origin such as the Varangian Guard, and the pronoia system was introduced. Palaiologan Byzantine army (1261–1453) The Palaiologan Byzantine army was named after the Palaiologos dynasty (1261–1453), which ruled Byzantium from the recovery of Constantinople from the Crusaders until its fall to the Turks in 1453. Initially, it continued some practices inherited from the Komnenian era and retained a strong native element until the late 13th century. During the last century of its existence, however, the empire was little more than a city-state that hired foreign mercenary bands for its defence. Thus the Byzantine army finally lost any meaningful connection with the standing imperial Roman army. Early Roman army (c. 550 to c. 300 BC) Until c. 550 BC, there was no "national" Roman army, but a series of clan-based war-bands which only coalesced into a united force in periods of serious external threat. Around 550 BC, during the period conventionally known as the rule of king Servius Tullius, it appears that a universal levy of eligible adult male citizens was instituted.