The right of the Pope to dispose of islands rested upon the donation of Constantine, which is now admitted to be as certainly spurious as Adrian's bull is certainly genuine. Adrian may have believed the donation authentic, but in any case, as Irish scholars point out, Constantine could not give what he had never possessed. It is true that Ireland never really formed part of the Roman Empire, but so strong was the idea of an oecumenical sovereignty that Celtic lawyers imagined a state of things in which Ireland would be tributary to the King of the Romans. This was a mere fiction, but it was one of which Rome would readily take advantage, and the Pope who insisted so sturdily on Barbarossa holding his stirrup was not the one in whose hands any available weapon would be allowed to rust.[30] [Sidenote: Henry II. finds a pretext for interference.] Henry II. was the most powerful prince in Europe, and sooner or later he was almost sure to have a reason for interfering in Ireland. The opportunity was at last afforded by Dermod MacMurrough, King of Leinster, who aspired to reign over all Ireland with the help of Anglo-Norman arms. As early as 1152 Dervorgil O'Melaghlin, wife of Tiernan O'Rourke, Prince of Brefny, being ill-treated by her husband, left him, and placed herself, her cattle, and her furniture under the protection of Dermod. Dervorgil was forty-four and Dermod sixty-two, so that the affair, in spite of a beautiful poem on the subject, was not what would be commonly called romantic. Yet Cleopatra was thirty-nine, when Antonius, at the age of fifty-three, refused to survive her. O'Rourke felt the insult and the loss of the lady, or, at least, of her property, and appealed to Tirlogh O'Connor, King of Connaught and titular King of Ireland. Dermod was compelled to abandon Dervorgil, who survived her husband eleven years, and died as late as 1193, during a pilgrimage to Mellifont Abbey. On the death of Tirlogh O'Connor his son Roderic became a candidate for the chief sovereignty, but Dermod espoused the cause of the O'Neill candidate, who was successful. The flight or abduction of Dervorgil was certainly not the proximate cause of the Norman invasion, but by placing Dermod in permanent opposition to O'Connor and O'Rourke, it probably contributed to bring it about. [Sidenote: Dermod MacMurrough.]