October 1, 1529: The Colloquy of Marburg, which attempted to unify the followers of Martin Luther and Ulrich Zwingli, begins. It would close in failure October 4. While the Reformers agreed on 14 of the 15 articles, they remained divided over the Lutheran doctrine of the Eucharist (consubstantiation). Thus Switzerland remained Reformed and Germany stayed Lutheran—and dreams of a united European front against Roman Catholicism died (see issue 39: Luther's Later Years).