The Roman Papacy was to become the instrument of the Imperial idea's revival in the West. The position of the Popes had been strengthened by the reconquest of Rome by Justinian, as the Emperors periodically reaffirmed the traditional primacy of the Bishop of Rome to check the potential political influence of the Patriarch of Constantinople. Furthermore, for various reasons, Catholicism finally triumphed over Arianism in the Western kingdoms: in the Visigothic Iberian Peninsula with the conversion of Reccared I in 587, and in Lombard-held Italy, after some back-and-forth, following the death of King Rothari in 652.