Who explored the Amazon River in Brazil?

The Amazon River was famously explored by European navigator Francisco de Orellana in the 16th century. In 1541, he undertook a journey that began in Quito, Ecuador, and led him down the river to the Atlantic Ocean, making him the first European to navigate its entire length. His expedition provided significant insights into the geography and biodiversity of the region, although it also marked the beginning of European exploitation of the Amazon. Other explorers, such as Henry Walter Bates and Theodore Roosevelt, later contributed to the exploration and study of the Amazon.