Read this: Parallel to events in Germany, a movement began in Switzerland under the leadership of Huldrych Zwingli. Zwingli was a scholar and preacher, who in 1518 moved to Zurich. Although the two movements agreed on many issues of theology, some unresolved differences kept them separate. A long-standing resentment between the German states and the Swiss Confederation led to heated debate over how much Zwingli owed his ideas to Lutheranism. The German Prince Philip of Hesse saw potential in creating an alliance between Zwingli and Luther. A meeting was held in his castle in 1529, now known as the Colloquy of Marburg, which has become infamous for its failure. The two men could not come to any agreement due to their disputation over one key doctrine.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): What did the Colloquy of Marburg become infamous for?
its failure