Italy. The nadir of the Byzantine army as a professional fighting force was reached in 1091, when Alexios managed to field only 500 soldiers from the Empire's regular soldiery. These formed the nucleus of the army, with the addition of the armed retainers of Alexios' relatives and the nobles enrolled in the army, plus the substantial aid of a large force of allied Cumans, which won the Battle of Levounion against the Pechenegs. Yet, through a combination of improved finances, skill, determination, and years of campaigning, Alexios, John, and Manuel Komnenos managed to restore the power of the Byzantine Empire, constructing a new army in the process. These developments should not, however, at least in their earlier phases, be seen as a planned exercise in military restructuring. In particular, Alexios I was often reduced to reacting to events rather than controlling them; the changes he made to the Byzantine army were largely done out of immediate necessity and were pragmatic in nature. The new force had a core of units which were both professional and disciplined. It contained guards units such as the Varangians, the vestiaritai, the vardariotai and also the archontopouloi (the latter recruited by Alexios from the sons of dead Byzantine officers), foreign mercenary regiments, and also units of professional soldiers recruited from the provinces. These provincial troops included kataphraktoi cavalry from Macedonia, Thessaly and Thrace, plus various other provincial forces. Alongside troops raised and paid for directly by the state the Komnenian army included the armed followers of members of the wider imperial family, its extensive connections, and the provincial aristocracy (dynatoi). In this can be seen the beginnings of the feudalisation of the Byzantine military. The Komnenian period, despite almost constant warfare, is notable for the lack of military treatise writing, which seems to have petered out during the 11th century. So, unlike in earlier periods, there are no detailed descriptions of Byzantine tactics and military equipment. Information on military matters in the Komnenian era must be gleaned from passing comments in contemporary historical and biographical literature, court panegyrics and from pictorial evidence. Size There are no surviving reliable and detailed records to allow the accurate estimation of the overall size of the Byzantine army in this period; it is notable that John Birkenmeier, the author of the definitive study of the Komnenian army, made no attempt to do so. He merely noted that while Alexios