Even if you have never heard of Albrecht Dürer you have seen this picture or the sculpture.  When Friedrich the Wise, a big art guy and Martin Luther’s protector, sent Dürer one of Luther’s books in 1520, Dürer wrote the Elector’s secretary: I pray Your Honor to convey my humble gratitude to His Electoral grace, and beg him humbly that he will protect the praiseworthy Dr. Martin Luther for the sake of Christian truth. It matters more than all the riches and power of this world, for with time everything passes away; only the truth is
eternal. And if God helps me to come to Dr. Martin Luther, then I will carefully draw his portrait and engrave it in copper for a lasting remembrance of this Christian man who has helped me out of great distress. And I beg your worthiness to send me as my payment anything new that Dr. Martin may write in German.

Dürer’s admiration for Luther was such that after the Diet of Worms, not knowing whether he was dead or alive, Dürer offered a
prayer: . . . if we have lost this man, who has written more clearly than any that has lived for 140 years, and to whom Thou hast given such a spirit of the Gospel, we pray Thee, O Heavenly Father, that Thou wouldst again give Thy Holy Spirit to another . . . O God, if Luther is dead, who will henceforth deliver the Holy Gospel to us with such clearness?  Unknown to Dürer at the time, Luther was very much alive and had been placed in hiding by his friends to protect him from capture by the imperial or papal forces.