This sculpture commemorates the air raid on Guernica April 26, 1937.It was carried out, at the behest of Francisco Franco's rebel Nationalist faction, by its allies, the Nazi German Luftwaffe's Condor Legion and the Fascist Italian Aviazione Legionaria, under the code name 'Operation Rügen'. The operation opened the way to Franco's capture of Bilbao and his victory in northern Spain..The attack gained controversy because it involved the bombing of civilians by a military air force, an action which a war correspondent at the time described as "unparalleled in military history".