Consecrated as the new capital of the Roman world in the year 330 ce, Constantinople was the ancient city of Byzantion, in origin a colony of Megara in Attica, and renamed the ‘city of Constantine’ by the first Christian emperor of the Roman world. He made it his capital in an effort to establish a new strategic focus for the vast Roman state, as well as to distance himself from the politics of the previous centuries. By the middle of the fifth century, the western parts of the Roman Empire were already in the process of transformation which was to produce the barbarian successor kingdoms, such as those of the Franks, Visigoths and Ostrogoths, and the Burgundians, while the eastern parts remained largely unaffected by these changes. When exactly ‘Byzantine’ begins and ‘late Roman’ ends is a moot point. Some prefer to use Byzantine for the eastern part of the Roman Empire from the time of Constantine I – that is to say, from the 320s and 330s; others apply it to the Eastern Empire from the later fifth or sixth century, especially from the reign of Justinian (527–65). In either case, the term ‘Byzantine’ legitimately covers the period from the late Roman era on, and is used to describe the history of the politics, society, and culture of the medieval East Roman Empire until its demise at the hands of the Ottomans in the fifteenth century.

The ages of humankind are designated by the material with which they made tools and weapons: stone, bronze, and iron. Remnants of these tools and weapons, found in archaeological excavations, are often the earliest evidence of existence in a place, especially before humans were able to express (and depict) themselves in words or art. Artistic depictions would follow, and then written ones, but both several thousands of years later. A wood, stone, or metal club, a stone or metal spearhead or arrowhead, a metal dagger or sword – and this appears to have been the progression – all could be used for hunting, likely their main function in pre-agricultural societies.

Although a battle zone from early in its history, the Roman province of Hispania began to undergo external military pressure in the fifth century ce with the invasions of the Visigoths, Suevi, and Vandals.1 Within a century, the Visigoths had come to dominate the Peninsula, establishing their capital at Toledo and exchanging their Arian brand of Christianity for Roman Catholicism.2 Like its Roman imperial predecessor, the Visigothic kingdom was structurally weak and revealed this instability each time a sovereign died. Rulers were seldom replaced without a civil war in which members of the royal family and their supporters fought for the throne. In the last of these struggles, Roderick (710–11) was opposed by the heirs of his predecessor, Watiza (701–10), led by Count Julian of Ceuta on the African litoral. Gathering a small army of Berber tribesmen, many of who had recently converted to Islam, Julian led an assault against Roderick in the late spring of 711. He was eventually disposed by Tarik ibn Zīyad, an agent of the Muslim governor of Tangier.3

It would not be very much of an overstatement to say that modern academic writing about medieval warfare – in English, at least – began with Sir Charles Oman, whose first essay on the subject was written in 1884 and later expanded into his History of the Art of War in the Middle Ages, which went through two editions (1898 and 1924). Oman’s brisk narrative weaving together weaponry, military institutions and exemplary battles is typical of the pioneering generation of literature on the subject – and not just in English, as attested by such works as Hans Delbrück’sGeschichte der Kriegskunst im Rahmen der politischen Geschichte (three editions between 1900 and 1920) and Ferdinand Lot’s L’Art militaire et les armées au Moyen Age en Europe et dans le Proche Orient (1946). Another characteristic shared by all of these early surveys is their lack of interest in the world beyond Europe, except to the extent that Europeans came into contact with that world through encounters such as the Crusades (as suggested by the wording of Lot’s title).

The history of Italian warfare from 1300 to 1500 has been dominated by discussion of mercenary soldiers. Italian states used them throughout the Middle Ages and by the fourteenth century the practice evolved into a species of “system,” characterized by reliance on preformed bands of substantial size, containing also foreign soldiers from outside of the peninsula. The era of the “companies of adventure” (compagnie di ventura), as it is known, lasted from roughly the second decade to the end of the fourteenth century. It was followed by the emergence in the fifteenth century of individual native mercenary captains, condottieri, who settled into regular service with states and were the precursor to more permanent armies by the middle of the century. The reliance on mercenaries rendered Italian warfare out of touch with developments elsewhere in Europe, and left the peninsula unprepared for the onslaught of the armies of France and Spain and the Italian Wars in the sixteenth century. The invasion of Italy in 1494 by the French king Charles VIII was the signal event that revealed the weakness of Italian military institutions and more generally the strength of the rising nation state over its evolutionary predecessor, the city-state.

The history of war in the Scandinavian world is inseparable from the history of the Vikings. The stereotype of Norse violence, still prevalent today, was fostered by contemporary writers such as Alcuin, who lamented the strike on Lindisfarne in his native Northumbria (793 ce) as a pagan contamination of Christian society. ‘The heathens’, he wrote to the monks there, ‘have stained the sanctuaries of God, poured forth the blood of the saints all around the altar, laid waste to the house of our hope, and trodden upon the bodies of the saints in the temple of God as if they were dung in the street. What can I say except to lament in spirit with you before the altar of Christ and say “spare your people, Lord, spare your people, and do not give your inheritance to the pagans lest they might say where is the God of the Christians”?’ A century later, a horrified Abbo of St Germain-des-Près recounted how so many Viking longships went down the Seine to Paris that the river itself seemed to have disappeared. According to the view presented in medieval sources from the British Isles and France and replicated in modern textbooks and popular histories, Scandinavians were decidedly ‘other’ to the Europe they plundered.

The Tang dynasty, which lasted from 618 to 907, was typical of China’s great imperial regimes in that it owed its creation to successful military action and saw its subsequent fortunes shaped to a very great extent by events on the battlefield; when its military power waned the dynasty faltered, and when that power had dissipated completely it fell. In the Tang, as under earlier and later dynasties, the ruling elites were intensely interested in matters of military policy and strategy, with military expenditures claiming the largest portion of the state’s revenues. For the Tang, as for all of the other dynasties, the image of Confucian sage kings ruling by moral suasion, without reference to force of arms, belongs to the realm of myth rather than reality.

The years around 1200 ce mark a significant turning point in the history of warfare in India, due to the decisive campaigns waged in northern India by the Ghurids of Afghanistan and the concomitant introduction of new forms of military culture from the eastern Islamic world. While limited parts of India’s periphery had been under Islamic rule long before this time, it was only under the Ghurids that Islamic control was established in the core region along the Ganga and Yamuna rivers (the “Ganga-Yamuna Doab”). A series of decisive battles was carried out here between 1192 and 1206, under the direction of Quṭb al-Dīn Aybeg, a Turkish slave commander (ghulām) in the service of the Ghurid sultan Mu‘izz al-Dīn Muḥammad bin Sām. Even after Mu‘izz al-Dīn’s death in 1206, Aybeg remained in India controlling the newly acquired Ghurid territories from his base in Lahore in the Punjab.

Anthropologists believe that the Japanese archipelago was settled by migrants from the Asian mainland sometime between 140,000 and 500,000 years ago, when falling global temperatures trapped water in glaciers and the polar ice caps, causing sea levels to drop 120 m or more below their present levels, and opening land bridges to Siberia and the Korean peninsula. Permanent village settlements and a cultural complex known as the Jōmon, after the distinctive, cord-marked slab pottery found at most sites, appeared between 14,500 and 10,000 bce. Around 1,000 bce, a new wave of immigrants spread outward from northern Kyushu, intermingling with the Jōmon peoples and displacing their civilization with a new one, which archaeologists have dubbed Yayoi after the location of the first site discovered, in Tokyo in 1884. The newcomers brought with them bronze- and iron-working skills, advanced agricultural techniques, and more sophisticated forms of political organization.

The Ottoman empire is named after Osman(d.1324), the eponymous founder of the dynasty, whose name came to be rendered in English as Ottoman. Osman was a Turkish frontier lord – beg in Turkish – who commanded a band of semi-nomadic fighters at the beginning of the fourteenth century in northwestern Asia Minor (Anatolia), known at the time to Turks, Persians, and Arabs as the land of Rum (Rome); that is, the land of the Eastern Roman Empire. Osman Beg was but one of many Turkish lords who carved out their respective principalities in western and central Asia Minor, profiting from the power vacuum caused by the Mongols’ destruction of the Seljuq sultanate of Rum in 1243.

The ways in which different medieval cultures justified war, theorized about war, and developed different customs that shaped the conduct of warfare varied widely. While the many “cultures of war” that emerged in the medieval world shared some basic characteristics, what is more broadly comparable are the processes or dynamics that shaped military cultures around the world. This chapter will explore, comparatively and as globally as the evidence allows, those dynamics and the cultural patterns they produced. It will argue that cultures of war emerged from a series of intersections between ideas about war on the one hand, and the various contexts within which wars happened – geographic, socioeconomic, and political – on the other. These intersections shaped cultures of war at the broadest level, and more specifically complicated the development of justifications of war, theories about war and its uses, and the customs that influenced the conduct of warfare within individual cultures.

The defining feature of Western warfare in this period was knighthood. This was not because horseback warfare was in any way new in the Frankish lands, or even because the technology of the equipment and use of cavalry had changed in any radical sense, though it is generally assumed that the stirrup appeared as a feature of cavalry equipment at some time in the ninth or tenth century, thus allowing the saddle to become a more effective fighting platform. But the stirrup did not by any means create the knight. What the knight represented was a new social phenomenon which grew progressively more important as generations passed and read new meanings into the status and potential of knighthood.

Over a span of three and a half centuries (1200–1550) Japan experienced profound transformations in the institutions, ideals, and methods of war. Originally a limited, clearly defined and extraordinary event, warfare became an endemic and encompassing element of life in the mid sixteenth century. Earlier, small bands of mounted warriors, skilled in archery, arrived in camp and departed as they saw fit, for no institutional mechanisms existed for them to supply themselves or their followers with food and materials of war. By the sixteenth century, however, powerful magnates (daimyō) were capable of supplying and maintaining large armies, numbering in the thousands, largely composed of pike-wielding foot soldiers.

The inhabitants of seventh-century Arabia mobilized for warfare in a manner new to that region of the Near East: the effort fell, albeit gradually, under central authority.1 Arabia had long been a highly variegated cultural zone, encompassing the Syrian Desert, southern Mesopotamia, and the Arabian Peninsula. Acting in tandem, largely nomadic tribal forces accepted the leadership of sedentary townsmen, the great number of whom belonged to the Quraysh, an influential tribe of two towns of the Hejaz region, Mecca and Medina. If Yemen and south Arabia had long known the rule of kings, and, hence, more formal military organization, only now did the central and northern stretches of the Peninsula and southern Syria experience what can thereby be considered as early state formation. The effort was driven by an equally untested set of ethical and spiritual teachings. A charismatic figure, Muḥammad ibn ʿAbdallāh (570–632), preached a strict monotheism; these teachings served as the seedbed of what would soon be known as Islam.

In popular perceptions, the later Middle Ages loom large as the apogee of medieval chivalry, epitomised by the foundation of chivalric orders, such as the Order of the Garter, by instructional texts such as the Livre de Chevalerie of Geoffroi de Charny, and by the chronicles of Jean Froissart (c.1337–c.1405), written