In the first half of the 7th century CE, the extent of the Byzantine Empire was greatly reduced by the conquests of the Rashidun Caliphate. It responded with a comprehensive reorganization of its armed forces (659–62) adopting structure and battle tactics that would remain intact until the crushing defeat at Manzikert (1071) by the Seljuk Turks, which triggered further reform. The Byzantines were students of warfare: Emperor Leo the Wise wrote a military manual prescribing specific tactics depending on the enemy. Nevertheless, their standard battle formation placed the infantry commands (chiliarchia) in the centre, with the heavy infantry (skoutatoi) to the fore, the archers to the rear. The flanks would be guarded by the cataphracta, armoured cavalry, who were also the army’s main offensive force looking to rout and/or envelop the enemy. Fanned out around the army would be light cavalry, responsible for scouting, screening, skirmishing and protecting the army’s rear and baggage train.
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