This medal commemorates the 300th anniversary of the imperial diet held in Speyer in 1529 at which five Lutheran princes issued a strong protest against the anti-Lutheran measures of Emperor Carl V as he sought to reverse the policy of religious tolerance adopted in 1526. The word Protestant orginated from this incident.
The passage, opened by King Maximilian I of Bavaria on May 27, 1823, was created in part by blasting into the rocky cliffs. The modeler Neuss was royal Bavarian court engraver and medallist for the City of Augsburg. He was also the owner of a private mint in Augsburg.