Following the traditions of the group, he kept this name secret until his death. Cadogan published several studies of the language, religion and culture of the Guaraní, becoming a recognized authority of this group. One of his most famous works is "Ayvu Rapyta," a collection of religious traditions of the Mbya-Guarani. His works were published in academic publications in Paraguay, Uruguay, Mexico, Argentina, Brazil, Austria, France and the USA. In 1949 President Felipe Molas López appointed him "Protector of Indians", but he later lost favour with the thuggish dictator Alfredo Stroessner who tried to politicize and dismantle the organization protecting the indigenous group. Cadogan died in 1973 after forty years dedicated to the Guaraní cause and denunciation of the systemic persecution and abuse they had been subjected to. His library was donated to the Catholic University of Asunción. Pursuant to municipal ordinance 9513/76, a street near his home was named after him. Paraguayans consider him as one of the 100 most important people of the millennium. Léon Cadogan's son Rodger Cadogan currently heads the Fundación Léon Cadogan, an organization that continues to advance the goals of Paraguay's Guaraní people. Suplemento Antropológico, Universidad Católica, revista del centro de estudios antropológicos. Vol.XXXIV no.2 diciembre 1999 ISSN 0378-9896 Homenaje a León Cadogan en el centenario de su nacimiento   . A peculiar People . Gavin Souter. Register in Australia, National Library of Australia. Registry number Aus-68-1177 SBN207 95037 7