Mbayá

Guaycuru came to be the collective name applied to all the ethnic groups speaking similar languages, called Guaycuruan, while the name Mbayá referred more narrowly to several loosely-organized bands of the northern Gran Chaco.

[6] In 1542, the Spanish Governor of Paraguay Álvar Núñez Cabeza de Vaca with Guarani allies launched a large military operation against the Mbayá northeast of Asunción.

[7] Over the next century, the Mbayá acquired by theft or trade horses and iron tools and weapons from the Spanish and became more threatening, especially to the Guarani who lived eastward from the Paraguay River.

In 1661, some of the Mbayá migrated east of the river, destroyed a Jesuit mission, also called a reduction, and displaced the Guarani in the old region of Itatín, located southwest of the present day city of Campo Grande, Brazil.

[8] The Mbayá and other Guaycuruan groups developed a horse culture, similar in many respects to that of the indigenous peoples of the Great Plains of North America.

While some made peace with the Paraguayans, in the northern Chaco the Mbayá bands contested Spanish authorities and Jesuits expanding out of Santa Cruz de la Sierra, Bolivia.

For the next 30 years, until 1793, the Mbayá menaced the Santo Corazon area, reduced the settlement to impotence, and retained effective control of the Bolivian Chaco.

[15] The Portuguese and the newly independent Brazilians provided them with arms and ammunition and bought the cattle and horses they stole from Paraguayan ranches.

[18] During and after the war, a smallpox epidemic decimated their population and with the influx of large numbers of Brazilian settlers, the Mbayá lost their lands and became laborers and ranch hands.

[20] The Guaná, (also called Chané and Layaná), speakers of an Arawak language, were vassals of the Mbayá, a relationship that, according to Spanish accounts, existed in 1548, and possibly much earlier.

In the early 18th century the Guaná lived in seven large villages of 1,000 or more people on the western side of the Paraguay River between 19 and 22 south latitudes.

The Mbayá augmented their numbers, strictly limited by late marriages and abortion, by intermarriage with Guaná and captive women of other ethnic groups.