When first approached by missionaries in 1757, the Cashibo killed one of them and forced the rest to flee. In 1870,
Shetebo and
Conibo people raided the Cashibo. There was a "decisive punitive expedition" against the Cashibo natives around the Pachitea River's connection with the Ucayali River on December 10, 1866. The Peruvian navy gunboats
El Morona,
El Napo and
El Putumayo retaliated against the Cashibo there because they attacked members of
El Putumayo when the crewmen disembarked to collect food from a native crop field. During the punitive expedition, women and children were captured and there was a massacre when around five hundred Cashibo men tried to attack the group of Peruvians returning to their gunboats. Hundreds of Cashibo men were killed from the gunboat's artillery. Until the 20th century, Cashibo avoided outside contact. In 1930, they numbered 4,000 but their population was reduced by diseases. Simón Bolívar Odicio dominated the Cashibo from 1930 to 1940. Odicio was a Cashibo who had been kidnapped and raised by the Shipibo. He encouraged the tribe to open a road into their territory, which brought on non-native settlement and rapid
acculturation, with devastating effects on the tribe. In 1940, the Peru government offered the surviving Cashibos a reservation; however, they declined, wishing to remain in their own homeland. ==Notes==