The indigenous peoples of the southern prairies, and in particular the Banda Oriental, are known through numerous chronicles and references. The main nations that are mentioned in the documents and references and that are considered the most numerous (with populations of more than 10,000 inhabitants each) are the Uruguayan nation and the nation of Mánán or Guenoa. However, in addition to these two peoples there were less
 numerous groups and that in some occasions they had decisive importance in the historical events of the European invasion in their territories. Following is a brief description of some of them.

Indigenous people of the southern grasslands


The yaros, yaroses or jacroas
At that time the yaros were one of the most important ethnic groups in both bands of Uruguay. Azara originally placed them on the eastern coast of the Uruguay River between the Negro River and the San Salvador. By 1655, their cacique Pedro Guaytán was summoned by the authorities of Buenos Aires (Barrios Pintos, p.88). In 1701 the federation of the native fighters commanded during the battle of the Yí and in 1715 they were mentioned like one of the main groups of Between Rivers in the failed campaign of Piedrabuena. In 1786 they were located on the coasts of Uruguay and at the tips of the streams Cuareim and Arapey (ref. Barrios Pintos, p.44). There is no reference to the yaros in the nineteenth century.

The Bohanes, Bojanes, Mbojas or Moxanes
The bohanes were another indigenous bias that according to Azara inhabited the valley of the Uruguay River north of the Negro River. Already in the seventeenth century is found allied to Yaros and Charruas and in 1655 his chief chief Lumillán was called to Buenos Aires to request his submission to the Catholic faith There are references to the Bohan in the Spanish documents of the campaigns of 1701 (battle of the Yí) where they are called "mbojas" and "moxanes", in the campaign of Entre Ríos de Piedrabuena and in other 18th century documents. There are references that the Bohan language was very different from the other indigenous languages. According to Azara the Bohans were a less numerous bias than the yaros that would have disappeared by the end of the 18th century. However, the Bohan language was still mentioned by Larrañaga as a "living" language in his inaugural address to the National Library in 1815, so it is presumed that there were still some Bohan families at that time.

The Mbatidas
The mbatidas were mentioned in the Spanish parts of the "battle" of the Yí. It was a confederated bias with Yaros, Bohanes and Charrúas that confronted the Spaniards during the first years of the 18th century. After those dates his name disappears from the chronicles very quickly.

The Martidans
They were a small pampa group that is mentioned in some documents. Lozano in his chronicle points out that among the Uruguayan peoples of barbarian customs were the Yaros, the Martidans and the Guenoas. References to the martidans are scarce and absent in the eighteenth century.

The Guayantiranes or Guaranquiranes
The Guayantiranes were an apparently quite numerous group from the Banda Oriental del Paraná located in the vicinity of the Guanquirarós stream in Entre Ríos. They had ambiguous links with the Charruas. There are a good number of Guayantiranes slaves registered in the Santa Fe register of 1665, probably a product of the "maloqueo" to which some "stray" Charrúas groups were dedicated. A certain number of these captives expressed that their nationality was Uruguayan. The term "guayantirán" ceased to be used in the course of the eighteenth century.

The Machados or Manchados
The Machados were a small group with charrúas connections whose duration was not very prolonged. According to López Monfiglio who quotes Pablo Cabrera, the machados received that name for being "of those of Captain Machado ... of the other Banda" according to a declaration of three charrúas of 1665. In the chronicles of the early 18th century, he considers him a group allied to the Charrúas but "peaceful". This bias disappeared in the mid-eighteenth century.

The Negueguianes or Negoes
It was a small group mentioned in some documents of the seventeenth and eighteenth centuries located on the eastern margin of the Paraná River according to references of Vera Mujica in Santa Fe in 1648. Already in the eighteenth century seem to have completely extinguished.

The Balomares, Mbaloma or Bolomares
The balomares were groups linked to the charrúas and yaros that inhabited the Entre Ríos at the beginning of the 18th century. A certain number of balomares appear as slaves or servants ("pieces") in the census of the city of Santa Fe in 1665, and some of them have a mixed Uruguayan-Uruguayan nationality. Since the middle of the eighteenth century its name is not registered anymore.