not he was on active campaign or garrison duty. The pronoiar also had a direct interest in keeping his 'fief' productive and in defending the locality in which it was situated. The local people who worked the land under a pronoiar also rendered labour services, making the system semi-feudal, though the pronoia was not strictly hereditary. It is very probable that, like the landowning magnates, pronoiars had armed retinues and that the military service that this class provided was not limited to the pronoiar himself. Though Manuel I extended the provision of pronoia, payment of troops by cash remained the norm. Structure Command hierarchy and unit composition Under the emperor, the commander-in-chief of the army was the megas domestikos (Grand Domestic). His second-in-command was the prōtostratōr. The commander of the navy was the megas doux (Grand Duke), who was also the military commander for Crete, the Aegean Islands and the southern parts of mainland Greece. A commander entrusted with an independent field force or one of the major divisions of a large expeditionary army was termed a stratēgos (general). Individual provinces and the defensive forces they contained were governed by a doux (duke) or katepanō (though this title was sometimes bestowed on the senior administrator below the doux), who was a military officer with civil authority; under the doux a fortified settlement or a fortress was commanded by an officer with the title kastrophylax (castle-warden). Lesser commanders, with the exception of some archaic titles, were known by the size of the unit they commanded, for example a tagmatarchēs commanded a tagma (regiment). The commander of the Varangians had a unique title, akolouthos (acolyte), indicative of his close personal attendance on the emperor. During the Komnenian period the earlier names for the basic units of the Byzantine cavalry, bandon and moira, gradually disappear to be replaced by the allagion (), believed to have been between 300 and 500 men strong. The allagion, commanded by an allagatōr, was probably divided into subunits of 100, 50 and 10 men. On campaign the allagia could be grouped together (usually in threes) into larger bodies called taxeis, syntaxeis, lochoi or tagmata. The infantry unit was the taxiarchia, a unit type first recorded under Nikephoros II Phokas; it was theoretically 1,000 men strong, and was commanded by a taxiarchēs. Guards units and the Imperial household Many of the earlier guard units did not survive the reign