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:
Alsace

Context:
By the time of the Protestant Reformation in the 16th century, Strasbourg was a prosperous community, and its inhabitants accepted Protestantism in 1523. Martin Bucer was a prominent Protestant reformer in the region. His efforts were countered by the Roman Catholic Habsburgs who tried to eradicate heresy in Upper Alsace. As a result, Alsace was transformed into a mosaic of Catholic and Protestant territories. On the other hand, Mömpelgard (Montbéliard) to the southwest of Alsace, belonging to the Counts of Württemberg since 1397, remained a Protestant enclave in France until 1793.

Question:
Who was known as a reformer in Strasbourg?

Martin Bucer