Bucer had met Martin Luther in 1518 and adopted his ideas."Martin Bucer (1491-1551)", on: Musée virtuel du Protestantisme français (Virtual museum of the French Protestantism), retrieved on 29 April 2013. He then helped implement the Reformation in the Free Imperial City of Wissembourg in Alsace, which resulted in his excommunication by George of the Palatinate, the bishop of Speyer, and his conviction as outlaw. In 1523 he found asylum in Strasbourg, where he set up Bible reading classes and later, in 1529, presented the Reformation. He received John Calvin, who had been expelled from Geneva in 1538. Bucer tried to safeguard the unity of the Church, but failed in reconciling Luther and Zwingli, or bringing Catholics and Protestants to agree at least on some points. At his urging, the city of Strasbourg granted asylum to the persecuted anabaptists. By 1525 the Reformation was gradually spreading not only into the countryside possessions of Strasbourg, but also into territories of other overlords.
