The Charrúa were an indigenous people or Indigenous Nation of the Southern Cone in present-day Uruguay and the adjacent areas in Argentina (Entre Ríos) and Brazil (Rio Grande do Sul). They were a semi-nomadic people who sustained themselves mainly through hunting and gathering. Since resources were not permanent in every region, they would constantly be on the move. Rain, drought, and other environmental factors determined their movement. For this reason they are often classified as seasonal nomads. The Charrúa people were massacred in a campaign in 1831 by the colonial forces in Uruguay known as the Massacre of Salsipuedes. Though largely erased from modern histories, some communities of the Charrúa survived outside of Uruguay in Argentina and Brazil. It is believed that there are approximately between 160,000 and 300,000 individuals in Uruguay, Argentina, and Brazil today who are descendants of surviving Charrúa. Contemporary descendants of the Charrúa have created organizations and advocate for the memory of the indigenous people. The life of the Charrúas before contact with the Spanish Colonists remains to a large extent a mystery since most knowledge about the Charrúas comes from Spanish contact with them. Chroniclers such as the Jesuit Pedro Lozano accused the Charrúan people of killing the Spanish explorer Juan Díaz de Solís during his 1515 voyage up the Río de la Plata. This was a crucial moment since it shows that the Charrúas were prepared to resist the Spanish invaders. Following the arrival of European settlers, the Charrúa, along with the Chana, strongly resisted the territorial invasion. In the 18th and 19th centuries the Charrúa were confronted by cattle exploitation that strongly altered their way of life, causing famine and forcing them to rely on cows and sheep. However, these were in that epoch increasingly privatized . Malones (raids) were resisted by settlers who freely shot any indigenous people who were in their way.