 He first arrived in Santo Domingo in 1517, sent there by Cardinal Jiménez de Cisneros to assist the friars of the Order of Jerome in the resolution of political problems in the Indies.In Santo Domingo, Zuazo wrote to Spanish King Charles I (Holy Roman Emperor Charles V) and William de Croÿ, Charles's chamberlain, to inform them of the hidden costs of slavery in the New World (January 22, 1518).At the same time, he recommended the importation of black slaves, even specifying the age at which they should be imported (15 to 20 years), and that they should marry.