William Adelin in the context of Battle of Brémule

Malcolm III (Middle Irish: Máel Coluim mac Donnchada; Scottish Gaelic: Maol Chaluim mac Dhonnchaidh; c. 1031–13 November 1093) was King of Alba from 1058 to 1093. He was later nicknamed "Canmore" (Scottish Gaelic: ceann mòr, lit. 'big head', understood as "great chief"). Malcolm's long reign of 35 years preceded the beginning of the Scoto-Norman age. Henry I of England and Eustace III, Count of Boulogne were his sons-in-law, making him the maternal grandfather of Empress Matilda, William Adelin and Matilda I, Countess of Boulogne. All three of them were prominent in English politics during the 12th century.

Malcolm's kingdom did not extend over the full territory of modern Scotland: many of the islands and the land north of the River Oykel were Scandinavian, and south of the Firth of Forth there were numerous independent or semi-independent realms, including the kingdom of Strathclyde and Bamburgh, and it is not certain what if any power the Scots exerted there on Malcolm's accession. Throughout his reign, Malcolm III led at least five invasions into English territory. One of Malcolm's primary achievements was to secure the position of the lineage that ruled Scotland until the late thirteenth century, although his role as founder of a dynasty has more to do with the propaganda of his descendants than with history. He appears as a major character in William Shakespeare's Macbeth, while his second wife, Margaret, was canonised as a saint in the thirteenth century.

Henry I (c. 1068 – 1 December 1135), also known as Henry Beauclerc, was King of England from 1100 to his death in 1135. He was the fourth son of William the Conqueror and was educated in Latin and the liberal arts. On William's death in 1087, Henry's elder brothers Robert Curthose and William Rufus inherited Normandy and England, respectively, thereby leaving Henry landless. He subsequently purchased the County of Cotentin in western Normandy from Robert, but his brothers deposed him in 1091. He gradually rebuilt his power base in the Cotentin and allied himself with William Rufus against Robert.

When William died in a hunting accident, Henry seized the English throne ahead of Robert, promising at his coronation to correct many of William's less popular policies. He married Matilda of Scotland and they had two surviving children, Empress Matilda and William Adelin. Robert disputed Henry's control of England and invaded from Normandy in 1101. The ensuing military campaign ended in a negotiated settlement that confirmed Henry as king. The peace was short-lived, however, and Henry invaded the Duchy of Normandy in 1105 and 1106, finally defeating Robert at the Battle of Tinchebray. Henry kept Robert imprisoned for the rest of his life. Henry's control of Normandy was subsequently challenged by Louis VI of France, Baldwin VII of Flanders and Fulk V of Anjou, who promoted the rival claims of Robert's son, William Clito, and supported a major rebellion in the Duchy between 1116 and 1119. Following Henry's victory at the Battle of Brémule, a favourable peace settlement was agreed with Louis in 1120.

The Anarchy was a civil war in England and Normandy between 1138 and 1153 which resulted in a widespread breakdown in law and order. The conflict was a war of succession precipitated by the accidental death of William Adelin—the only legitimate son of King Henry I—who drowned in the White Ship disaster of 1120. Henry sought to be succeeded by his daughter, Empress Matilda, but was only partially successful in convincing the nobility to support her. On Henry's death in 1135, his nephew Stephen of Blois seized the throne with the help of his brother Henry of Blois, who was the bishop of Winchester. King Stephen's early reign saw fierce fighting with disloyal English barons, rebellious Welsh leaders, and Scottish invaders. Following a major rebellion in the southwest of England, Matilda invaded in 1139 with the help of her half-brother Robert of Gloucester.

In the initial years of civil war, neither side achieved a decisive advantage; Matilda came to control southwest England and much of the Thames Valley, while Stephen remained in control of the southeast. Barons who refused to support either side held much of the country. The castles of the period were easily defensible, so the fighting was mostly attrition warfare comprising sieges, raiding and skirmishing. Armies mainly consisted of knights and infantry, many of them mercenaries. In 1141 Stephen was captured following the Battle of Lincoln, causing a collapse in his authority over most of the country. When Matilda attempted to be crowned queen, she was forced instead to retreat from London by hostile crowds; shortly afterwards, Robert of Gloucester was captured by Stephen's wife, Matilda of Boulogne, at the rout of Winchester. The two sides agreed to a prisoner exchange, swapping the captives Stephen and Robert. Stephen then almost captured Matilda in 1142 during the Siege of Oxford, but she escaped from Oxford Castle across the frozen Thames to safety.

Stephen (1092 or 1096 – 25 October 1154), often referred to as Stephen of Blois, was King of England from 22 December 1135 to his death in 1154. He was Count of Boulogne jure uxoris from 1125 until 1147 and Duke of Normandy from 1135 until 1144. His reign was marked by the Anarchy, a civil war with his cousin and rival, the Empress Matilda, whose son, Henry II, succeeded Stephen as the first of the Angevin kings of England.

Stephen was born in the County of Blois in central France as the fourth son of Stephen-Henry, Count of Blois, and Adela, daughter of William the Conqueror. His father died as a crusader while Stephen was still young, and he was brought up by his mother. Placed into the court of his uncle Henry I of England, Stephen rose in prominence and was granted extensive lands. He married Matilda of Boulogne, inheriting additional estates in Kent and Boulogne that made the couple one of the wealthiest in England. Stephen narrowly escaped drowning with Henry I's son, William Adelin, in the sinking of the White Ship in 1120; William's death left the succession of the English throne open to challenge. When Henry died in 1135, Stephen quickly crossed the English Channel and took the throne with the help of his brother Henry, Bishop of Winchester, arguing that the preservation of order across the kingdom took priority over his earlier oaths to support the claim of Henry I's daughter, the Empress Matilda.

The White Ship (French: la Blanche-Nef; Medieval Latin: Candida navis) was a vessel transporting many nobles, including the heir to the English throne, that sank in the English Channel near the Normandy coast off Barfleur during a trip from France to England on 25 November 1120. Only one of approximately 300 people aboard, a butcher from Rouen, survived.

Those who drowned included William Adelin, the only legitimate son and heir of Henry I of England; his half-siblings Matilda FitzRoy and Richard of Lincoln; Richard d'Avranches, Earl of Chester; and Geoffrey Ridel. With William Adelin's death, the king had no obvious successor, and his own death 15 years later set off a succession crisis and a period of civil war in England known as the Anarchy (1135–1153).