Stephen, King of England Robert of Gloucester rebelled against the King, starting the descent into civil war in England. An illegitimate son of Henry I and the half-brother of the Empress Matilda, Robert was one of the most powerful Anglo-Norman barons, controlling estates in Normandy as well as the Earldom of Gloucester. He was known for his qualities as a statesman, his military experience, and leadership ability. Robert had tried to convince Theobald to take the throne in 1135; he did not attend Stephen's first court in 1136 and it took several summons to convince him to attend court at Oxford later that year.
Norman conquest of England the invasion, intermarriage between the native English and the Norman immigrants had become common. By the early 1160s, Ailred of Rievaulx was writing that intermarriage was common in all levels of society. The impact of the conquest on the lower levels of English society is difficult to assess. The major change was the elimination of slavery in England, which had disappeared by the middle of the 12th century. There were about 28,000 slaves listed in "Domesday Book" in 1086, fewer than had been enumerated for 1066. In some places, such as Essex, the decline in slaves was 20 per cent