King Stephen

... was in fact the only monarch from the House of Blois. (Matilda was a Norman, and is included in this table for convenience only.)

Stephen's mother, Adela, was the ninth and last child (and fifth daughter) of William I. His father was Stephen II, Count of Blois. Blois was a city and county south of Paris; the Counts of Blois also held the city and county of Chartres.

Henry I's only legitimate male heir was William Adelin, who died in 1120 when the White Ship struck a submerged rock in the English Channel off Barfleur, Normandy, and sank. Only one person on board survived. Henry entered negotiations to name Stephen (his nephew) as his heir, but then named his daughter Matilda instead.

In 1135, when Henry died, Stephen decided to assert his claim to the English throne. He invaded England and had himself crowned. The period that followed is known as The Anarchy, with open warfare between the respective supporters of Stephen and Matilda both in England and on the Continent for almost 20 years.

Matilda invaded England in 1139, and was proclaimed queen by her supporters. Civil war continued for another 14 years, before Stephen was finally recognised as king, with Matilda's son Henry (Henry II) as his successor. Henry II's father (Matilda's husband) was Geoffrey V, Count of Anjou; Henry was the first English monarch from the house of Anjou.

By the time Henry's grandson came to the throne as Henry III, the family had lost most of their continental possessions and so they became known as the Plantagenets. (Geoffrey of Anjou wore a sprig of broom – planta genista in Latin – in his hat.) This name has been retrospectively applied to English kings from Henry II onwards.