This chapter provides an overview of the first treaties adopted by the eight Amazon States, from the time they attained independence from the European colonial powers, mostly by the end of the nineteenth century (except for Guyana and Suriname) until 1978, the year of the adoption of the Amazon Cooperation Treaty (ACT). Signed by two or more Amazon States, those instruments were aimed mainly at establishing their common boundaries and setting up rules on commerce and navigation. Some few agreements and resolutions concluded, for instance at inter-American conferences, had the objective of promoting technical, scientific, and cultural cooperation, particularly in border areas. Such instruments paved the way for other forms of cooperation, of which the 1969 La Plata River Basin Treaty and the 1978 ACT are examples.

INTERNATIONAL BOUNDARIES DELIMITING THE AMAZON REGION

The papal bull Inter Caetera of 1493 issued by Alexander VI provided a first delimitation line between the Spanish and Portuguese possessions in the New World. Portugal, however, challenged this bull as being favorable to the Kingdom of Castile. As a result, negotiations began for achieving a new boundary line and a year later the two kingdoms agreed on a boundary treaty signed on June 7, 1494 in the Spanish town of Tordesillas. This treaty drew a line running from north to south, 370 leagues west of the Cape Verde Islands, and provided that everything west of this line should belong to Spain and everything east of it to Portugal.