A dictionary of Spanish history and culture
The transterrados were Spanish intellectuals who were forced to leave Spain because of the defeat of the Republic in 1939, and who settled in Latin America, where a similar culture and the same language allowed them to continue working. Latin America was seen as an extension of Spain, and so they could claim they had not been desterrado, banished from their land, but had rather moved within the same land. They form a key part in the Spanish intellectual diaspora. The term was coined by Spanish philosopher, José Gaos, and is often applied specifically to Mexico, considered the capital of exiled Spain.
More here “El término fue acuñado por el filósofo español José Gaos (1900-1969). Designa a aquellos filósofos y pensadores que llegaron a México como consecuencia de la derrota de la República Española (1836-1939).”