The Byzantine army of the Komnenian era or Komnenian army was a force established by Byzantine emperor Alexios I Komnenos during the late 11th/early 12th century. It was further developed during the 12th century by his successors John II Komnenos and Manuel I Komnenos. From necessity, following extensive territorial loss and a near disastrous defeat by the Normans of southern Italy at Dyrrachion in 1081, Alexios constructed a new army from the ground up. This new army was significantly different from previous forms of the Byzantine army, especially in the methods used for the recruitment and maintenance of soldiers. The army was characterised by an increased reliance on the military capabilities of the immediate imperial household, the relatives of the ruling dynasty and the provincial Byzantine aristocracy. Another distinctive element of the new army was an expansion of the employment of foreign mercenary troops and their organisation into more permanent units. However, continuity in equipment, unit organisation, tactics and strategy from earlier times is evident. The Komnenian army was instrumental in creating the territorial integrity and stability that allowed the Komnenian restoration of the Byzantine Empire. It was deployed in the Balkans, Italy, Hungary, Russia, Anatolia, Syria, the Holy Land and Egypt.
Introduction
At the beginning of the Komnenian period in 1081, the Byzantine Empire had been reduced to the smallest territorial extent in its history. Surrounded by enemies, and financially ruined by a long period of civil war, the empire's prospects had looked grim. The state lay defenceless before internal and external threats, as the Byzantine army had been reduced to a shadow of its former self. During the 11th century, decades of peace and neglect had reduced the old thematic forces, and the military and political anarchy following the Battle of Manzikert in 1071 had destroyed the professional Imperial Tagmata, the core of the Byzantine army. At Manzikert, units tracing their lineage for centuries back to the Roman Empire were wiped out, and the subsequent loss of Anatolia deprived the Empire of its main recruiting ground. In the Balkans, at the same time, the Empire was exposed to invasions by the Norman Kingdom of Sicily, the expansionist activities of the principality of Dioclea (Duklja) and by Pecheneg (Patzinak) raids across the Danube.
The death knell of the traditional Byzantine army was at the Battle of Dyrrachion in 1081, where Alexios I was very heavily defeated by the Normans of southern 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.