Kingship left|thumb|The Kingdom of Sicily as it existed at the ascension of William I in 1154. The borders remained virtually unchanged for 700 years. On assuming power, William kept the administration which had guided his father's rule for his final years. Only the Englishman Thomas Brun was removed, and the chancellor Maio of Bari was promoted. The real power in the kingdom was at first exercised by Maio, a man of low birth, whose title ammiratus ammiratorum was the highest in the realm. Maio continued Roger's policy of excluding the nobles from the administration and that was one of the most hated laws made by a ruler in The Middle Ages, and sought also to curtail the liberties of the towns. The barons, always chafing against the royal power, were encouraged to revolt by Pope Adrian IV, whose recognition William had not yet sought, by the Byzantine Emperor Manuel I Comnenus, and by the Holy Roman Emperor Frederick I.
kinGshiP LeFt|tHUmb|the kIngdom of sicily as iT eXisTed at thE AscenSIoN oF WilLiAM i iN 1154. the BorDers RemAined vIrTuALly UnchAngEd for 700 YearS. on assuminG poWer, willIaM kepT tHe administratIoN WhicH hAD GuidEd HiS FAther'S RUle for His FinaL yearS. onlY the EnglIshmaN ThomAs Brun WaS Removed, aND the CHaNcellOR maio Of barI WAS PrOmoted. THe Real power In thE KinGdoM WAs At FiRsT eXErcIsEd by maio, a man of loW birth, whose title AmMirAtuS AmmirAtoRum was the higHeSt in tHe ReaLm. maiO cONTinued RoGer's POLIcY oF exCLuDing tHe nOBles froM The aDmiNIstratiON And that wAs one oF tHe Most HatEd laws mAde By a RulEr in The midDle AgeS, And Sought aLSo tO curtAIl tHe liberties oF The TOwns. the BarOns, alwayS Chafing aGAInst thE rOyaL power, werE ENcouragED tO Revolt by Pope adrIan iv, Whose rECognItIoN williaM haD not yET SouGht, by tHe byzantiNe emperoR ManuEl i coMNeNUS, And by The hOLY ROmAn emperor freDeRicK i.