Christopher Columbus
Since the late 20th century, historians have criticized Columbus for initiating colonization and for abuse of natives. Among reasons for this criticism is the poor treatment of the native Taíno people of Hispaniola, whose population declined rapidly after contact with the Spanish. Columbus required the natives to pay tribute in gold and cotton. Modern estimates for the pre-Columbian population of Hispaniola are around 250,000–300,000. According to the historian Gonzalo Fernandez de Oviedo y Valdes, by 1548, 56 years after Columbus landed, and 42 years after he died, fewer than 500 Taíno were living on the island. The indigenous population declined rapidly, due primarily to the first pandemic of European endemic diseases, which struck Hispaniola after 1519. The natives had no acquired immunity to these new diseases and suffered high fatalities. There is also documentation that they were overworked.
Catholic Church and the Age of Discovery
After the discovery of the Americas, many of the clergy sent to the New World began to criticize Spain and the Church's treatment of indigenous peoples. In December 1511, Antonio de Montesinos, a Dominican friar, openly rebuked the Spanish rulers of Hispaniola for their "cruelty and tyranny" in dealing with the natives. King Ferdinand enacted the "Laws of Burgos" and "Valladolid" in response. However enforcement was lax, and the New Laws of 1542 took a stronger line. This caused a revolt among the Spanish colonists, and the alarmed government backed down, softening the effect of the laws. Some historians blame the Church for not doing enough to liberate the Indians; others point to the Church as the only voice raised on behalf of indigenous peoples. The issue resulted in a crisis of conscience in 16th-century Spain. The reaction of Catholic writers such as Bartolomé de Las Casas and Francisco de Vitoria led to debate on the nature of human rights and the birth of modern international law. (French, English, and Dutch reactions against the maritime monopolies granted to Portugal and Spain, meanwhile, culminated in Hugo Grotius's work articulating the doctrine of freedom of the seas.)