“MONSTROUS AND ILLEGAL PROCEEDINGS”: LAW ...

habit of conducting armed raids deep into the Banda Oriental for wild cattle. Much of this
bounty was then sold back to Spanish merchants or exported through Colônia to northern
Brazil. The Portuguese also actively developed alliances with indigenous tribes throughout
the borderlands. They encouraged raids on Spanish cattle herds and outposts. The
borderlands became a tumultuous and violent space. 5
As the Spanish and Portuguese empires rubbed against each other in the Río de la
Plata, imperial officials in their metropôles worked to mitigate their increasingly costly
defense obligations by clarifying the blurred boundaries between their possessions. Through
the Treaty of Madrid (1750) and the Treaty of San Ildefenso (1777), the two sides attempted
to resolve centuries-old ambiguities between the Iberian empires in the Río de la Plata’s
eastern reaches. The two treaties, however, did little to prevent conflicts on the ground.
Throughout the 1760s and 1770s, the rival empires traded Colônia between them as they
jostled for position at the river network’s mouth. As they swapped possessions along the
coasts, the Jesuit missions in the interior equally became a chip in imperial negotiations and
conflicts. When the Spanish offered up Jesuit lands to the Portuguese under the Treaty of
Madrid, the Order and their Indian allies bucked imperial calculations and openly defied
Portuguese expansion. The Portuguese ultimately crushed the indigenous rebellions after
bitter fighting. With the Jesuits now representing an independent source of power
inconsistent with both empires’ designs to consolidate their positions in the region, the
Spanish and Portuguese worked to end the mission project. In the 1760s, the Iberians
expelled the Jesuits from their empires altogether. With the collapse of the missions, the
surviving Guaraní population drifted out into the borderlands. These groups blended with
5 Guilhermino Cesar, História do Rio Grande do Sul: Período Colonial (Porto Alegre:
Editôra Globo, 1970), 85-88.
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