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 recognize the legitimacy of Afonso's adoption of the royal title in 1139, and continued to regard him as a vassal of the kingdom of León. On December 13, 1143, Afonso wrote Pope Innocent II the letter Claves Regni (Latin for 'Keys of the Kingdom'), declaring his decision to enfeoff Portugal to the Holy See and asking for protection against any interference in Portugal's territory. On May 1, 1144, Pope Lucius II replied by letter Devotionen Tuam (Latin for 'Your Devotion') and stated that he recognized Afonso's devotion, but still referred to Portugal as a land instead of a kingdom, and to Afonso as duke instead of a king.
