The encomienda system was a feudalistic governing structure in which South and Central American natives were attached to land headed by an encomiendero. The natives were to provide labor and tribute, while the encomiendero was supposed to protect them and educate them in the facets of Christianity. In reality, the natives were abused and enslaved.
When the conquistadores presented the Spanish crown with a conquered new land, they also presented a quandary: how to govern a vast new territory without setting up a rival government. The Spanish king decided to create vast landholdings that would be presented to the conquistadores, rewarding them while also creating a decentralized governing structure answerable primarily to the king. Unfortunately, the conquistadores were not beneficent landowners but brutal soldiers who cared little for the indigenous inhabitants.
Abuses arose swiftly. Natives were forced to work the fields or mines of encomienderos, regardless of any prior skills or social position. Those who fled were hunted down, killed or tortured. If crops failed, the natives were expected to produce tribute or face egregious punishment, which could result in death. Mining conditions were horrific. The Spanish overseers did not care how many natives died obtaining gold and mercury, so long as they obtained it. Even priests who were endowed with encomiendas fell prey to corruption, often living with native women and engaging in the same kind of torture as the conquistadores. After several decades, the Spanish king passed the New Laws, leading to the nearly as abusive repartimiento system, which made erstwhile encomiendas directly subject to the crown.