 On 22 December 1741, Pope Benedict XIV promulgated the papal bull "Immensa Pastorum Principis" against the enslavement of the indigenous peoples of the Americas and other countries.In spite of a stronger condemnation of unjust types of slavery by Pope Gregory XVI in his bull "In supremo apostolatus" issued in 1839, some American bishops continued to support slave-holding interests until the abolition of slavery.In 1866 The Holy Office of Pope Pius IX affirmed that, subject to conditions, it was not against divine law for a slave to be sold, bought or exchanged.