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In 1894, the altar-piece of the Poor Clares was moved to a new location behind the medieval high altar. In 1905, the Utrecht-based artist Wilhelm Mengelberg was commissioned to paint the back of the altar-piece, which was now visible. The resulting painting is an example of Late Neo-Gothic art in the cathedral. The Holy Trinity can be seen in a mandorla at the centre of the canvas panel surrounded by seraphim and symbols of the world. The four Evangelists and their symbols can be seen in the tracery-decorated spandrels at the corners of the vision-like image of the Holy Trinity.