On September 10, 1981, Spanish artist Pablo Picasso's monumental anti-war mural Guernica is received in the town of Guernica, whose suffering during the Spanish Civil War inspired the painting. In 1937, with the approval of Francisco Franco, Nazi Germany tested its deadly new air force on Guernica, a town in the independent-minded Basque region. In three hours of bombing, one-third of its 5,000 inhabitants were killed. In protest, Picasso painted Guernica from his exile in Paris. In 1939, the painting went to New York, where it remained, in accordance with Picasso's wishes, until democracy returned to Spain. It is now housed in the Reina Sofia Museum in Madrid. Since 1997, Basque nationalists have been calling for its transfer to the Guggenheim Museum in Bilbao.