Manifestis Probatum (Latin for 'Manifestly proven') is a papal bull and the founding document of Portugal. On 23 May 1179 Pope Alexander III promulgated the bull. The bull officially recognized the independence of Portugal from Leon by confirming the Kingdom of Portugal to, the now recognized, king Afonso Henriques and his successors. The bull is, therefore, the single most important written document from Portugal's independence process. The Papacy did not at first recognize the legitimacy of Afonso's adoption of the royal title in 1139, instead continuing to regard him as a vassal of the kingdom of León. On December 13, 1143, Afonso sent to Pope Innocent II the letter Claves Regni (Latin for 'Keys of the Kingdom'), in which he tells him that he has decided to enfeoff Portugal to the Holy See and asks him for protection against any interference in Portugal's territory. On May 1, 1144, Pope Lucius II in his letter Devotionen Tuam (Latin for 'Your Devotion') replying to Afonso, declared that he recognizes his devotion, but still refers to Portugal as a land and not a kingdom and refers to Afonso as duke of Portugal and not as king, thereby, failling to recognize the kingdom. The switch in papal policy in 1179 was justified by Afonso's reconquest of lands to the south of the Iberian Peninsula to which no other Christian monarch had claim. Source: Wikipedia (en)