Tannhäuser was a travelling German poet and knight that discovered the subterranean home of Venus. He spent one full year worshipping the goddess. Filled with remorse, he left Venusberg for Rome to ask Pope Urban (1261-1264) if it was possible to be absolved of his sins. 

Pope Urban emphatically told Tannhäuser that forgiveness was as impossible as it would be for his papal staff to blossom. Three days after the knights departure, the Pope’s staff bloomed with flowers. Urban immediately sent a messenger to find Tannhäuser, but it was too late. The knight had returned to Venusberg never to be seen again. 

Stanislaw Jakub Rostworowski – Tannhäuser and Venus 1895. John Collier – In the Venusberg 1901.