Stephen (king from 1135-1154) was nephew to Henry I and a grandson of William the Conquerer. When his uncle Henry died, Stephen rushed to England and was crowned in London while Matilda, Henry I's daughter - and heir - was still in France.
Many of the barons were happy to go back on their promise to support Matilda as they did not believe a woman could rule, and they did not want to be controlled by her husband Geoffrey of Anjou. Stephen's rule was marked by civil war called 'the Anarchy' as Matilda's supporters fought for her claim to the throne.
In 1141, London was captured by Matilda, but Matilda argued with her officials and was forced to leave the City without being crowned.
In an attempt to bring the years of fighting to an end, following the death of his eldest son Eustace in 1153, Stephen agreed to recognise Matilda's son Henry Fitzempress as his heir.
And so, when Stephen died in 1154, Henry succeeded unchallenged.