This behavior started with his learning of the execution of Johann Esch and Heinrich Voes, the first individuals to be martyred by the Roman Catholic Church for Lutheran views, prompting Luther to write the hymn "Ein neues Lied wir heben an" ("A new song we raise"), which is generally known in English by John C.
What hymn did Luther write after the martyrdom of Esch and Voes?
Ein neues Lied wir heben an