Switzerland's Protestant churches on Sunday began celebrating the 500th anniversary of the birth of John Calvin, a formative figure in the Reformation.
Born in France, Calvin spent some 20 years of his adult life in Switzerland's western city, transforming Geneva into a base for French Protestantism and an intellectual centre of Europe.
He reinforced the link between humanist thought and Christian convictions.
"Calvin, the visionary Reformer, sparked off a movement which has spread to the four corners of the earth: more than 80 million Christians living in 107 countries today acknowledge his legacy," said Setri Nyomi, the general secretary of the World Alliance of Reformed Churches.
Nyomi, the association's first non-European head, was joined at the Reformers' Wall in Geneva by officials from the Swiss Protestant Church Federation and by representatives of Reformed congregations from around the world.
Organisers of the Calvin Jubilee 2009 year will hold public exhibitions, courses and concerts leading up to a ceremony in Geneva next June.