Francisco de Orellana was a Spanish explorer and conquistador born around 1511. He is best known for leading the first European expedition to navigate the entire length of the Amazon River in the 1540s. Orellana's journey began as part of a larger expedition to find gold in South America, but it turned into a remarkable exploration of the region's vast waterways. During his expedition, Orellana encountered various indigenous tribes and documented their cultures and lifestyles. His travels contributed significantly to European knowledge of the Amazon rainforest and its biodiversity. Orellana's adventures paved the way for future explorations and colonization efforts in the area.