The bulls issued by Pope Alexander VI: Eximiae devotionis (3 May 1493), Inter caetera (4 May 1493) and Dudum Siquidem (23 September 1493), granted rights to Spain with respect to the newly discovered lands in the Americas similar to those Pope Nicholas V had previously conferred on Portugal with the bulls Romanus Pontifex and Dum Diversas. Morales Padron (1979) concludes that these bulls gave power to enslave the natives. Minnich (2010) asserts that this "slave trade" was permitted to facilitate conversions to Christianity. Other historians and Vatican scholars strongly disagree with these accusations and assert that Alexander never gave his approval to the practice of slavery. Other later popes, such as Pope Paul III in Sublimis Deus (1537), Pope Benedict XIV in Immensa Pastorium (1741), and Pope Gregory XVI in his letter In supremo apostolatus (1839), continued to condemn slavery. Inter Caetera was applied in the Requerimiento which was read to American Indians (who could not understand the colonisers' language) before hostilities against them began. They were given the option to accept the authority of the Pope and Spanish crown or face being attacked and subjugated. In 1993, the Indigenous Law Institute called on Pope John Paul II to revoke Inter Caetera and to make reparation for "this unreasonable historical grief". This was followed by a similar appeal in 1994 by the Parliament of World Religions.