Henry I (king from 1100-1135) was the youngest son of William the Conqueror. He had not received anything in his father's will but when his brother William II died in 1100 (some people believe Henry may have had a role in organising his brothers death), Henry inherited the crown.
Unlike his brother and father, Henry was a popular king. He abolished unpopular laws and decreased taxes, extended the justice system and lessened the power of the Norman barons (wealthy noblemen who had come over to England with William the Conqueror and been given large parcels of land) over their English subjects.
Despite having more illegitimate children than any other King (at least 25), William had only one son. In 1120, tragedy struck when the "White Ship" on which William Adelin, the king's son and heir, was sailing, sank with the loss of over 300 lives including the prince.
Despite remarrying, Henry never had another legitimate son and he made the barons of England swear an oath to accept his daughter Matilda as ruler on his death.
Henry died in 1135 in France. He is supposed to have become ill after eating too many lampreys (a fish). His body was brought back to to England and buried at Reading Abbey.
Following Henry's death there was the civil war known as 'the anarchy' as Matilda (Henry's daughter) and Stephen (Henry's nephew) fought over the throne.