8 jan 1455 ano - Pope Nicholas V publishes Romanus Pontifex, an encyclical addressed to King Afonso V of Portugal, which sanctions the conquest of non-Christian lands, and the reduction of native non-Christian populations to 'perpetual slavery'. (Later there will be a dramatic reversal when, in 1537, the bull Sublimis Deus of Pope Paul III forbids the enslavement of non-Christians.) (Linha do tempo)