1160–1191), italianised as Gualtiero Offamiglio or Offamilio from Latin Ophamilius, was the archdeacon of Cefalù, dean of Agrigento, and archbishop of Palermo (1168–1191), called "il primo ministro", the first minister of the crown.
Nevertheless, without the support of the queen regent or of the influential Thomas Becket, his faction bribed Pope Alexander III into confirming his election and he was consecrated in the Cathedral of Palermo on 28 September.
He accompanied William to Taranto to await his Byzantine bride and, failing that, he crowned Joanna, daughter of Henry II of England, as queen consort on 13 February 1177.
The pope issued the first of a short series of bulls favouring the cause of creating a new archdiocese in Sicily, centred on the Benedictine Cluniac abbey of Monreale, a recent foundation of William's.
Although he supported Constance to succeed William II, at the request of Pope Clement III, he had to crown Tancred of Lecce king in his cathedral in early January 1190.
He has been reckoned a leader of the feudatories against which all Sicilian kings fought for their royal prerogatives and, by Ferdinand Chalandon, as an imperialist who supported Henry in order to stand opposed to the inevitable civil war.