In 1928 the dirigible Italia under the command of Umberto Nobile left for the North pole. The expedition ended in disaster and all the blame for the catastrophe was put on Nobile's shoulders.
One of the first to defend him was the Czech participant of the expedition - František Běhounek. He did many to defend Nobile's reputation and Nobile did not forget.
The two men remained friends for the rest of their lives. Their correspondence, now preserved in Czech Technical University Archives, has been the basis for this article.