The Cardinal was not amused. When Gerhard Richter, one of the world’s most expensive living artists, designed an abstract stained glass window for Cologne Cathedral, Cardinal Joachim Meisner could barely conceal his anger.

“It belongs in a mosque or another house of prayer, not this one,” fumed the city’s Catholic Cardinal, who chose to attend an engagement in Poland when the window was unveiled. “If we are going to have a new window, then it should be one that reflects our faith, not just any faith.”

Politicians say that the Cardinal is aggravating tensions with Islam, while other churchmen say he is trying to stir up an ancient debate about how one should depict and visually pay tribute to God. Mr Richter, meanwhile, feels deeply misunderstood. “I would not have been able to work for a mosque,” said the 75-year-old, whose paintings are sold frequently for millions of pounds at auction. For the past three years he has been ranked as one of the top-earning artists in the world by Capital magazine and he has been hailed as “the Picasso of the 21st century”.

Mr Richter, who lives in Cologne, selected the order of the 11,200 individual panes of glass by random computer generation. The intention was to show that what appears to be coincidence is part of a divine design. The window is huge, spanning 110 sq m (1,200 sq ft), and when the sun shines in, the church is dappled with shades of red, blue, green and yellow.

The Cardinal would have preferred a saint or two.

The original window, sponsored by the Hohenzollerns, the Prussian royal family, depicted mediaeval heroes. Cardinal Meisner wanted the window to be replaced with glass paintings of the saints Maximilian Kolbe and Edith Stein - both of whom perished at the hands of the Nazis. But the supervisors of the cathedral settled on Mr Richter’s abstract design.

Islam has a tradition of barring the depiction of living beings in sacred spaces and the Cardinal clearly believes that Mr Richter has gone too far towards the Islamic iconoclasm. The atmosphere is raw in Cologne because of the popular opposition to a new mosque for the city’s 120,000 Muslims. The plans include high minarets that could visually challenge the towers of the cathedral, which reach a height of 157 metres. The Cardinal has gone on record about that too: “It leaves me with an uneasy feeling.”

The new window is garnering widespread praise, from the mayor, Protestant churchmen and art critics. Only the Cardinal, who has to celebrate Mass in the cathedral, has qualms.

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