Hermenegild Peiker (restorer)
The Martyrdom of St. Peter
Church of St. Peter, Munich, Germany
The triangle at the top represents the Trinity. Below it, the Church holds symbols of God's gifts to Mankind, the chalice representing the sacraments, and the book representing sacred scripture. Further down, an angel descends with a crown and palm branch, symbolizing martyrdom, for St. Peter, who is being crucified upside-down under the direction of Roman soldiers. I am not sure who is represented by the people watching the crucifixion from across a stream.
The original fresco was painted by Johann Baptist Zimmermann in 1753-56. It was destroyed in the bombings of World War II.
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Photographed at the church by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.