Detailed Instructions: Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.
Problem:Passage: Luther's hymns were frequently evoked by particular events in his life and the unfolding Reformation. 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. Messenger's translation by the title and first line 'Flung to the Heedless Winds' and sung to the tune Ibstone composed in 1875 by Maria C. Tiddeman. Question: What caused Luther to write hymns?
Solution:
events in his life