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.
Bartolomé de las Casas
Las Casas worked there in adverse conditions for the following months, being constantly harassed by the Spanish pearl fishers of Cubagua island who traded slaves for alcohol with the natives. Early in 1522 Las Casas left the settlement to complain to the authorities. While he was gone the native Caribs attacked the settlement of Cumaná, burned it to the ground and killed four of Las Casas's men. He returned to Hispaniola in January 1522, and heard the news of the massacre. The rumours even included him among the dead. To make matters worse, his detractors used the event as evidence of the need to pacify the Indians using military means. The tragic outcome of Las Casas's great mainland adventure made him turn his life in a new direction.