You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Martin_Luther

Context:
Without Luther's backing for the uprising, many rebels laid down their weapons; others felt betrayed. Their defeat by the Swabian League at the Battle of Frankenhausen on 15 May 1525, followed by Müntzer's execution, brought the revolutionary stage of the Reformation to a close. Thereafter, radicalism found a refuge in the anabaptist movement and other religious movements, while Luther's Reformation flourished under the wing of the secular powers.

Question:
What protection caused Luther's Reformation to flourish?

the secular powers