Juan Belaieff
Juan Belaieff (Russian: Ива́н Тимофе́евич Беля́ев, romanized: Ivan Timofeyevich Belyaev; 19 April 1875 – 19 January 1957) was a Russian and Paraguayan explorer, cartographer and soldier, notable for his investigation and mapping of the Gran Chaco region and for his role in the Paraguayan army during the Chaco War.