Laudabiliter was a bull issued in 1155 by Pope Adrian IV, the only Englishman to have served in that office. Existence of the bull has been disputed by scholars over the centuries; no copy is extant but scholars cite the many references to it as early as the 13th century to support the validity of its existence. The bull purports to grant the right to the Angevin King Henry II of England to invade and govern Ireland and to enforce the Gregorian Reforms on the semi-autonomous Christian Church in Ireland. Richard de Clare ("Strongbow") and the other leaders of the Norman invasion of Ireland (1169 – 71) claimed that Laudabiliter authorised the invasion. These Cambro-Norman knights were retained by Diarmuid MacMorrough, the deposed King of Leinster, as an ally in his fight with the High King of Ireland, Ruaidrí Ua Conchobair. Successive kings of England, from Henry II (1171) until Henry VIII (1541), used the title Lord of Ireland and claimed that it had been conferred by Adrian's successor, Pope Alexander III (c. 1100/1105 – 1181). After almost four centuries of the Lordship, the declaration of the independence of the Church of England from papal supremacy and the rejection of the authority of the Holy See required the creation of a new basis to legitimise the continued rule of the English monarch in Ireland. In 1542, the Crown of Ireland Act was passed by both the English and Irish parliaments. The Act established a sovereign Kingdom of Ireland with Henry as King of Ireland. A competing, Catholic claim to sovereignty in Ireland was issued in 1555, through Pope Paul IV's bull "Ilius, per quem Reges regnant", which bestowed the crown of the Kingdom on Philip II of Spain and Mary I of England. Text Papal bull A bull is a papal letter that takes its name from the leaden seal attached to it. The original bulla was a lump of clay moulded around a cord and stamped with a seal. When dry, the container could not be violated without visible damage to the bulla, thereby ensuring the contents remain tamper-proof until they reach their destination. Stephen J. McCormick, in his preface to The Pope and Ireland, notes that it was well known that the forgery of both Papal and other documents was fairly common in the 12th century. Citing Professor Jungmann, who in the appendix to his Dissertationes Historiœ Ecclesiasticœ,