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.
Kingdom of England Norman conquest of England, however, some Norman lords began to attack Wales. They conquered and ruled parts of it, acknowledging the overlordship of the Norman kings of England but with considerable local independence. Over many years these "Marcher Lords" conquered more and more of Wales, against considerable resistance led by various Welsh princes, who also often acknowledged the overlordship of the Norman kings of England. Edward I defeated Llywelyn ap Gruffudd, and so effectively conquered Wales, in 1282. He created the title Prince of Wales for his heir, the future Edward II, in 1301. Edward I's conquest was brutal and