De Orellana

De Orellana took about 57 men, the boat, and some canoes and left Pizarro’s troops on 26 December 1541. However, De Orellana missed
the confluence (probably with the Aguarico) where he was searching supplies for his men. By the time he and his men reached another village, many of them were sick from hunger and eating “noxious plants”, and near death. Seven men died in that village.
His men threatened to mutiny if the expedition turned back to attempt to rejoin Pizarro, the party being over 100 leagues downstream at this point. He accepted to change the purpose of the expedition to discover new lands in the name of the king of
Spain, and the men built a larger boat in which to navigate downstream. After a journey of 600 kilometres (373 mi) down the Napo River, they reached a further major confluence, at a point near modern Iquitos, and then followed the upper Amazon, now known as the
Solimões, for a further 1,200 kilometres (746 mi) to its confluence with the Rio Negro (near modern Manaus), which they reached on 3 June 1542.