INTRODUCTION Anglo-Norman England has long been a fertile subject for the study of medieval military history. Its preeminence is due in large measure to the events of 14 October 1066, during which William, duke of Normandy, wrested control of England away from Harold Godwinson at the Battle of Hastings. The result was a wave of changes that permanently altered the land of the Anglo-Saxons. Many of these changes directly influenced the methods by which the English crown conducted warfare, including the advent of a baronage and the importation of a feudal system of military obligation, both introduced after William’s coronation on Christmas 1066. William brought a policy of conquest and domination to England that defied compar- ison to the former Anglo-Saxon kingdoms. The Old English kings fought primarily defensive battles to preserve the Heptarchy against Viking and Danish expansion from the ninth to the eleventh century. In these endeavors the Saxons were only partially successful; the strong West Saxon-Kentish state built by Alfred (879–899) grew to include lands in the uncertain regions of Northumbria and Mercia, but the advent of the Danelaw and the return of Viking invasions in the late tenth century eroded the stability of the country. By the eleventh century Edward the Confessor (1042–1066) and his earls were struggling to maintain England’s borders in the rebellious west and north. In the years after Hastings, William solidified his reign through military operations such as the 1070 ‘harrying of the north’ with the Scots, as well as diplomatic moves that gained him the fealty of Welsh princes in 1081. Furthermore, because William retained his ducal rights to Normandy, under his rule England’s interests were formally linked to the Continent. Following his death in 1087, the Anglo-Norman royal line would mirror the hereditary success of the French Capetians, and until the deposition of Richard II on 29 September 1399 England’s crown enjoyed, with only one exception,1 1 This was the reign of Stephen of Blois, the nephew of Henry I (1100–1135), who ruled during the ‘anarchy’ in which he struggled with Henry I’s daughter and co-claimant Matilda; her son, Henry fitz Empress, gained the crown in 1154 and restored the original line of succession, albeit through a female. There were also 2 introduction direct familial succession through its Anglo-Norman, Angevin, and Plantagenet kings. These and other achievements followed the Norman conquest of England. William the Conqueror’s victory at Hastings has captured the imaginations of student and soldier alike, for it was one out of a rel- atively small number of major, decisive battles fought during the Middle Ages. Harold’s defeat meant the loss of life and crown as well as the transfer of England to an already-powerful duke, and few moments in history were encapsulated in the course of such a singular event. William’s career in Normandy and Brittany before 1066 set the stage for England’s entrance into the context of conti- nental warfare. The first proper encounter between the Anglo-Saxon infantry and the Norman bowmen and cavalry in 1066 has likewise been regarded as a case study for the conduct of eleventh-century warfare, and the tactics applied at Hastings have been the foci of Anglo-Norman military study for decades. William’s disputes with the Capetians and other local rulers in Brittany, Maine, and Normandy did not disappear after his coronation; king or not, he was still legally a vassal of Philip I of France (1060–1108), so the governance of these other provinces remained points of contention.2 Yet the English crown offered resources enough for William to improve his military footing and retain his holdings in Europe, and for the first time England became directly involved in continental politics. William’s sons William Rufus (1087–1100) and Henry I both intervened in continental lands with varying degrees of success, but the military nature of those struggles departed significantly from the decisive Battle of Hastings. Instead, long campaigns were settled bloodlessly in treaties, pitched battles were forsaken in favor of land-scourging tac- tics, and castles replaced armies as the effective measure of territo- rial control.3 These changes and others have encouraged the historical study of warfare during the remainder of the Anglo-Norman period and beyond. The present study addresses a portion of this timeframe succession disputes between William Rufus and his brother Robert Curthose (1087), Robert and his other brother Henry I (1100), and between John and Arthur of Brittany (1199). 2 For his warfare pre-1066, see D. C. Douglas, William the Conqueror (Berkeley, 1964), 133–55; and J. Gillingham, “William the Bastard at War,” in ANW, 143–60. 3 S. Morillo, Warfare under the Anglo-Norman Kings, 1066–1135 (Woodbridge, 1994), 1–2..