Collegiate Church of St. Stephan, known in German as St. Stephan zu Mainz, was originally built in 990 at the order of Archbishop Willigis, who also initiated the building of Mainz Cathedral. The church was founded on top of the highest hill in the town, most likely on behalf of Theophanu, the widow of Otto II, Holy Roman Emperor. Willigis intended the church to be a site of prayer for the Empire. St. Stephan Mainz (St. Stephan Church in Mainz) is famous for its Marc Chagall windows