John Calvin arrived. In 1541, he founded the Republic of Geneva on his own ideals. It became known internationally as the Protestant Rome and housed such reformers as Theodore Beza, William Farel or Pierre Viret. Zürich became another reform stronghold around the same time, with Huldrych Zwingli and Heinrich Bullinger taking the lead. Anabaptists Felix Manz and Conrad Grebel also operated there. They were later joined by the fleeing Peter Martyr Vermigli and Hans Denck. Other centres included Basel (Andreas Karlstadt and Johannes Oecolampadius), Berne (Berchtold Haller and Niklaus Manuel), and St. Gallen (Joachim Vadian). One canton, Appenzell, was officially divided into Catholic and Protestant sections in 1597. The larger cities and their cantons (Bern, Geneva, Lausanne, Zürich and Basel) used to be predominantly Protestant. Central Switzerland, the Valais, the Ticino, Appenzell Innerrhodes, the Jura, and Fribourg are traditionally Catholic. The Swiss Constitution of 1848, under the recent impression of the clashes of Catholic vs Protestant cantons that culminated in the Sonderbundskrieg, consciously defines a consociational state, allowing the peaceful co-existence of Catholics and Protestants. A 1980 initiative calling for the complete separation of church and state was rejected by 78.9% of the voters. Some traditionally Protestant cantons and cities nowadays have a slight Catholic majority, because since about 1970 a steadily growing minority were not affiliated with any religious body (21.4% in Switzerland, 2012) especially in traditionally Protestant regions, such as Basel-City (42%), canton of Neuchâtel (38%), canton of Geneva (35%), canton of Vaud (26%), or Zürich city (city: >25%; canton: 23%). Literature The earliest forms of literature were in German, reflecting the language's early predominance. In the 18th century, French became fashionable in Bern and elsewhere, while the influence of the French-speaking allies and subject lands increased. Among the classic authors of Swiss literature are Jeremias Gotthelf (1797–1854) and Gottfried Keller (1819–1890). The undisputed giants of 20th-century Swiss literature are Max Frisch (1911–91) and Friedrich Dürrenmatt (1921–90), whose repertoire includes Die Physiker (The Physicists) and Das Versprechen (The Pledge), released in 2001 as a Hollywood film. Famous French-speaking writers were Jean-Jacques Rousseau (1712–1778) and Germaine de Staël (1766–1817). More recent authors include Charles Ferdinand Ramuz (1878–1947), whose novels describe the lives of peasants and mountain dwellers, set in a harsh environment, and Blaise Cendrars (born Frédéric Sauser, 1887–1961). Italian and Romansh-speaking authors also contributed to the Swiss literary landscape, generally in proportion to their number. Probably the most