IN THE EARLY MIDDLE ages in England succession was not hereditary. Conquest, descent, and the agreement of the feudal lords all played their part in determining who gained the royal title; for a century before the story opens the crown had usually been seized by armed force.
In 1066 Duke William Bastard sailed from Normandy to England, defeated the Saxon king, Harold, at the Battle of Hastings, and claimed the English crown by right of conquest.
In 1087, King William I died, to be succeeded in England by his second son, William Rufus, and in Normandy by his eldest son, Robert. His youngest son, Henry, was left silver but no land. Although Robert, Duke of Normandy, fought his brother, William, for the English crown, he was unsuccessful.
In 1100, King William Rufus was killed in a hunting accident under questionable circumstances. His elder brother, Robert, was away on the First Crusade, and the throne was seized without opposition by his younger brother, Henry. Despite rumors that Henry was an accessory to his brother’s death, had even arranged it, nothing was ever proved. Nine centuries later historians still debate the issue. As one noted British historian, Christopher Brooke, summed it up: If William Rufus’s death in August 1100 was an accident, Henry I was an exceptionally lucky man.*
In 1106 Henry invaded Normandy, defeated his eldest brother, Robert, then imprisoned him for life, thus becoming Duke of Normandy as well as King of England as his father had been.
Henry married a Scottish princess, Matilda, of the old royal Saxon line, and by her had three children. One died in infancy; the other two, twins, a boy and girl, survived. Henry I begat numerous bastards but the twins, descended through the male line of William the Conqueror, remained his only legitimate children. His son, William, was named heir to the English throne and the Duchy of Normandy. But in the event that anything should happen to him, who then would rule?
* Christopher Brooke, The Norman and Saxon Kings.