The Heart of Glass

‘The Heart of Glass’: Modern Stained-Glass Windows in Germany

The potential and limits of art-historical research

Reinhard Köpf, Department of Art History, Heinrich-Heine-University Düsseldorf


Fig. 1. Johan Thorn Prikker, The Archangel Michael, Neuss, Church of the Three Kings, about 1912 © Jürgen Wiener

In this article I would like to draw attention to a research initiative that has recently begun at the Department of Art History of the Heinrich-Heine-University Düsseldorf and which will be further expanded in the coming years. The aim is to develop, research and propose strategies for the preservation of artistically designed stained glass windows from classical modernism to the present. After the end of the Second World War, Germany suffered immense losses in the field of artistically designed windows. However, from the middle of the twentieth century onwards, the gradual start of reconstruction measures led to a flood of new orders and innovative design ideas. The density of evidence of modern stained glass in the Rhineland after 1945, to which I will restrict myself in this article, is unique.((The term ‘Rhineland’ is used loosely to refer to an unspecified region, which in this article most closely resembles the area of the Prussian Rhine province in the nineteenth century, which was concentrated on the Middle to Lower-Rhine. The volumes Meisterwerke der Glasmalerei des 20. Jahrhunderts im Rheinland (I) and Meisterwerke der Glasmalerei des 20. Jahrhunderts in den Rheinlanden (II + III), edited by Iris Nestler, Mönchengladbach, 2015-2019, provide the basis for further research.)) Most of the famous artists of the period were represented; their designs, often for the most avant-garde buildings of their time, were executed by local workshops of international standing. Johan Thorn Prikker’s windows (Fig. 1) for the Church of the Three Kings in Neuss (from 1912) and those of Georg Meistermann in the staircase hall of the WDR radio station in Cologne (1952) represent the birth of modern stained glass before and after the Second World War. Düsseldorf is another place, along with Cologne, Neuss or Krefeld, that can lay claim to world renown in this respect, although awareness of the city’s examples of modernist stained glass works must first be awakened.((A first attempt is being made to raise awareness of Düsseldorf’s modernist stained glass, see: Jürgen Wiener and Reinhard Köpf (eds) Moderne Glasmalerei Düsseldorf. Glasfenster und ihre Künstler, Mönchengladbach, forthcoming autumn 2020.)) Because some examples are now, like their predecessors, threatened by destruction, either through modern restoration concepts or even through their complete demolition.((Andreas Barz refers to the loss of substance as a result of energetic training, to name just one aspect: Andreas Barz, ‘Alles rastert – oder die Nachkriegsmoderne wird historisch’, Kunsttexte 2/2012, pp. 1-4, (, accessed 16.07.2020, p. 3.))

Old fashioned, but not yet historical. A case study.

Fig. 2. Joachim Klos, Dalle de verre window, Düsseldorf-Urdenbach, The Holy Spirit Church, about 1965, view from the outside © Jürgen Wiener

Fig. 3. Joachim Klos, Dalle de verre window, Düsseldorf-Urdenbach, The Holy Spirit Church, about 1965, detailed view from inside © Jürgen Wiener

The Holy Spirit Church in Düsseldorf-Urdenbach, located in a southern district of the capital of North Rhine-Westphalia, possesses a treasure that hardly anyone has yet noticed. Built in 1965 in the brutalist style, the church has two unique dalle de verre windows (Figs 2 and 3) by the artist Joachim Klos (1931-2007), who is considered one of the world’s most influential post-war German glass artists.((See most recently Eva-Maria Willemsen and Waltraud Hagemann, Joachim Klos. 1931-2007. Grafiker und Glasgestalter, Mönchengladbach, 2017. Robert W. Sowers has argued that “during the 1950s and ’60s Germany produced the first authentic school of stained glass since the Middle Ages” (Robert W. Sowers, ‘Stained glass: 20th Century’, Encyclopædia Britannica, online edn, 6 May 2020., accessed 16.07.2020). Also, an exhibition in Swansea (Wales) in 1980 ranked Klos among the “magnificent seven” of modern glass painting, alongside Georg Meistermann, Ludwig Schaffrath, Johannes Schreiter, Wilhelm Buschulte, Jochem Poensgen and Hubert Spierling. Suzanne Beeh-Lustenberger, Justinus Maria Calleen and Thomas Heyden (eds) Lichtblicke. Stained glass of the 20th century in Germany, catalogue of exhibition in the German Stained Glass Museum, Linnich, 29.11.1997-13.4.1998, Linnich, 1997, p. 32f.)) Together with one of the most traditional glass workshops in Germany, the Hein Derix company from Kevelaer, on the Germany–Netherlands border,((The workshop Hein Derix KG Kevelaer has been in Kevelaer since 1886. The company was founded in 1866 by Wilhelm Derix in Goch (also Lower Rhine-region). The German Museum of Glass Painting, Linnich, dedicated an exhibition to the company in 2010, ‘Im Fokus der Moderne: Die Glasmalerei-Werkstatt Hein Derix, Kevelaer’,, accessed 16.07.2020.)) Klos created two room-high “window sculptures”, whose innovative potential not only defies all conventions in the field of dalle de verre windows, but also in the modernist glass art of the time.((On dalle de verre glazing, see: Marlies Schupp, ‘Das Betonglasfenster’, Das Münster 19, 1966, pp.137-140; Sandra Wagner, ‘Strahlende Farben gebannt in Beton. Die Betonglastechnik der 50er Jahre’, Die 50er Jahre – Halbzeit der Moderne, Kunst und Kirche 4,1998, pp. 229-235; Kai Kappel, ‘Selbstleuchtende Wände: Betonglas im Sakralbau/Luminous Walls: Concrete-and-glass composite construction in ecclesiastical architecture’, Detail 2, 2001, pp. 198-202 (article in German and English); Christoph Sander, Markus Kleine et al, ‘Betondickglasfenster. Schadensmechanismen und Instandsetzungsprinzipien zur Erhaltung’, Restauro 7, 2011, pp. 48-53. Recently, Ulrike Hoffmann-Goswin also was not able to determine and classify the window more precisely, in Sakrale Glasmalerei der 1960er bis 1980er Jahre in Deutschland, Regensburg, 2019.))

The two concrete and glass walls, which are supported by a concrete framework, consist of concrete panels worked in relief on both sides, creating different three-dimensional levels. White, yellow and blue glass rods, about 10 cm long, have been inserted through each of the panels, projecting beyond the concrete to varying degrees, on both the inside and outside.((Cf. Willemsen/Hagemann 2017 (see note 3), p. 95f.)) In this way, the transmission of daylight does not have the effect of a back-lit mosaic, as is the case with other types of dalle de verre windows, but rather projects individual points of light into the almost dark interior, as if guided by small channels from outside to inside. There is nothing comparable, even elsewhere in artist’s extensive body of work. Only the chapel of the retirement home on Bettratherstraße in Mönchengladbach, whose dalle de verre windows Klos designed almost at the same time as the Düsseldorf example, showed a corresponding conceptual idea in the treatment of the concrete walls as monumental reliefs. Yet the Bettratherstraße scheme was much more conventional in its overall design.

Sadly, the Bettratherstraße chapel was demolished in 2004. The days of the Holy Spirit Church are also numbered. In 2020, just fifty years after it was constructed, the church will be demolished, to make way for a home for the elderly. The unique windows of Joachim Klos will disappear. Neither the adaptation of the building in a manner that preserves the historically significant elements, nor the relocation of the windows, are being considered, due to the expected high costs of such solutions.((Since the Holy Spirit Church is not an object entered in the list of monuments, i.e. legally it does not have monument status, the bodies responsible for monument protection, in this case, the Lower Monument Authority of the City of Düsseldorf and the specialist office of the Rhineland Regional Council, are unable to intervene.))

Should it stay or should it go now…?

The two examples discussed above, as well as numerous other cases,((For example, a list of demolished sacral monuments is provided under the heading “invisibilis – The church retriever” at:, accessed 16.07.2020.)) make it clear that the handling of cultural resources has taken on a somewhat arbitrary character. I deliberately do not speak only of listed buildings, which in Germany have been protected by a legal framework since the end of the 1970s (and since 1990 in eastern Germany). However, it must be noted that we are now witnessing the erosion and more generous interpretation of these regulations, which is increasingly driving the disappearance of historic buildings, especially in the field of post-war architecture.((Recently, the need to respond to the problem has at least been recognized. In a growing body of literature, nothing less than a radical rethink in the field of heritage protection is up for debate. See Ingrid Scheurmann, ‘Erinnern und Vergessen in Zeiten von „Big Data“. Zu den Prämissen aktueller Denkmal- und Erbediskurse’, in Kai Kappel and Matthias Müller (eds), Geschichtsbilder und Erinnerungskultur in der Architektur des 20. und 21. Jahrhunderts, Regensburg, 2014, pp. 131-147; Ingrid Scheurmann, ‘Herausforderung Nachkriegsarchitektur. Zum denkmalpflegerischen Umgang mit Gebäuden der 1950er bis 1970er Jahre’,, accessed 16.07.2020. The latter offers numerous further references to current discourses.)) As a similar trend is evident in the treatment of stained glass of this period, I will briefly outline the issues driving this trend.((One of the few scholars, if not the only one, who has dealt with the relationship between glass windows and the preservation of historical monuments in more detail is Holger Brülls. See Holger Brülls, ‘Künstlerische Lösungen für denkmalpflegerische Probleme? Zum Verhältnis von moderner Glasmalerei und zeitgenössischer Denkmalpflege, Die Denkmalpflege 62, issue 2, 2004, pp. 125-140, in which Brülls is primarily interested in the design of historical rooms with modern windows.)) However, in the context of heritage preservation, windows, although an integral part of architecture, nevertheless should step out of the shadow of the buildings in which they are located, and to whose fate they are often tied when the question of sustainable protection arises. In discussing current attitudes to twentieth-century historic buildings, I will limit myself to Germany. Nevertheless, our project adopts a European perspective and we can certainly expect similar problems across the European community. We must also distinguish between secular and sacred buildings, and here I will concentrate on the latter.

Fig. 4. Gottfried Böhm, Church “Mary, Queen of Peace”, Velbert-Neviges, from 1965-1972 © LVR-Amt für Denkmalpflege im Rheinland, Jürgen Gregori

In no other region of Europe were so many new churches built after the Second World War, as in the Rhineland and the neighbouring Ruhr area. This unique architectural heritage is not primarily characterised by the number of buildings, but rather by its diversity and architectural quality. However, in contrast to the churches built before 1945, 86 percent of which are listed buildings, to date only 9 percent of the modern churches have been listed.((Ursula Kleefisch-Jobst, Karen Jung and Peter Köddermann (eds), Fluch & Segen. Kirchen der Moderne, exhibition booklet, Museum für Architektur und Ingenieurkunst (M:AI) NRW, 2019, p. 63-65.)) Explanations for this are uncertain, especially since the discussions about the value of the sites in question as places, or even monuments, have only intensified in recent years. A first major inventory campaign, from 2009 to 2014, has now covered the church buildings of the post-war period in North Rhine-Westphalia.((For descriptions and discussion of the campaign, see Godehard Hoffmann ‘Moderne Kirchen in Düren und im Rheinland – ein Überblick’, Zwischen Stolz und Vorurteil: Nachkriegskirchen im Rheinland. Doku­mentation zum 4. Rheinischen Tag für Denkmalpflege in Düren am 10. Mai 2015, Announcements from the LVR Office for Monument Preservation in the Rhineland, issue 22, pp. 17-32 and Oliver Meys ‘Das Inventarisationsprojekt als wichtiges Instrument für die denkmalfachliche Bewertung des Nachkriegskirchenbaus’, ibid., pp. 33-44. Both online at:, accessed 16.07.2020. In other regions of Germany, comparable surveys are still pending.)) Despite this, a certain scepticism about these buildings can still be observed, perhaps because they do not yet seem to be anchored in the collective cultural memory of architectural history to the same extent as earlier buildings.

However, attitudes to some of Gottfried Böhm’s buildings demonstrate that modernist buildings are being adopted as part of the collective architectural memory. Böhm’s signature work, the 1965-1972 pilgrimage church, Maria, Königin des Friedens (Mary, Queen of Peace), in Velbert-Neviges (Fig. 4), which incidentally also contains important windows by the architect, is a key example. The building’s architecture, which is more reminiscent of a sculpture, revolutionized the spatial character of modern churches.((Cf. most recently Stefanie Lieb, Sakralbauten der Architektenfamilie Böhm, Regensburg, 2019, pp. 414-423.)) Although it suffers from some structural problems today, the church, which is already a listed building, is now widely accepted because of its ingenious construction and unique appearance.

Nevertheless, the examples of the Holy Spirit Church, Düsseldorf, and the Bettratherstraße chapel demonstrate that not all modernist buildings are lucky enough to be perceived as part of the cultural identity in time to secure their future. A first assessment could be that yesterday’s buildings seem to lack the familiarity of the ancient, with which one might associate care and preservation. Subliminally, however, the old is played off against the new, by reproaching the modern architecture of the 1960s and 1970s for its lack of innovative power compared to contemporary buildings. By labelling such buildings “old fashioned”, there is an inherent value judgement in favour of their abandonment or destruction. As Ingrid Scheurmann has argued, “Appropriation only becomes possible at a distance, namely when that what was previously perceived as different and foreign has become part of the cultural identity”.((Scheurmann, ‘Herausforderung Nachkriegsarchitektur’, n.p. (see note 9).))

As the example of the Holy Spirit Church in Düsseldorf has shown, there is cause for concern about the legacy of the last two generations of architects, because satisfying solutions have not yet been found for the difficulties of selecting, evaluating and dealing with the numerous post-war buildings they created.((The discussion is also a philosophical one. As early as 1900, the philosopher and sociologist Georg Simmel described the feeling of modern people, who felt increasingly alienated from their cultural environment, as “being surrounded by a myriad of cultural elements which are not meaningless to him […], but which are also not meaningful in the deepest sense”. See Georg Simmel, ‘Der Begriff und die Tragödie der Kultur’, in Michael Landmann (ed.), The Individual Law. Philosophical Excursuses, Frankfurt am Main, 1968, pp. 116-147, esp. p.144.)) While these difficulties primarily concerned the architecture of the first two decades after the Second World War as the putative flagships of state heritage conservation, the artistically designed stained glass windows of that period, which are inextricably linked to the surrounding architecture, have not yet received the same attention.

Rooms with a view… and perspectives

I shall now turn to consider artistically designed glass windows. Evidently, such windows, like other interior fittings and decoration, have so far been little discussed in contemporary debates regarding the values and protection of twentieth-century monuments/historic buildings. The windows of Johan Thorn Prikker (Fig. 5) in the foyer of the Museum Kunstpalast, Düsseldorf, reconstructed after their loss in the war (first version: 1925, second version: 1983/84), or those of Josef Albers in the staircase of the Grassi Museum in Leipzig (first version: 1926, second version: 2011)(( For an overview of the reconstruction, see on the webpage of the company Peters (Paderborn), who undertook the new work:, accessed 16.07.2020.)) are suitable cases for reflecting upon our assessment of such incunabula of modern glass art.

Fig. 5. Johan Thorn Prikker, Window in the foyer of the Museum Kunstpalast Düsseldorf (Inv. No. LP1984-34) © Kunstpalast – ARTOTHEK

Our definition and understanding of monuments, and the values associated with them, have never been bindingly established and are changing against the background of advancing globalisation. We should therefore consider whether our definitions and conceptions are still sufficient to do justice to these special types of artwork. In particular, we must no longer dismiss such works as mere “decoration”. The recent change towards the current, comparatively unspecific, albeit internationally more compatible, concept of cultural heritage preservation increasingly seems to be supplanting the concept of monument protection; this change has shifted issues of categorisation and recognition of the artistic value of stained glass, yet it has not resolved them. In reality, stained glass windows influenced contemporary art forms; for example, links can be drawn between their degree of abstraction, or ornamentation, and movements such as Art Informel (Informalism) and Op Art. Consequently, the artistic value of such windows demonstrates that they warrant recognition as significant artworks.((This idea has not yet been sufficiently appreciated. The neglect of glass as a vehicle for innovative art forms is, to a certain extent, due to the lack of recognition within the art world. There is no market for glass windows and there is limited trade in stained glass; at any rate, contemporary windows are hardly ever found on the art market. The positioning of stained glass as a craft, rather than fine art, as it still seems to be most commonly perceived, undoubtedly contributes to this situation.))

Fig. 6. Annette Jansen-Winkeln, Forschungsstelle Glasmalerei des 20. Jahrhunderts e. V., Screenshot of the webpage

If we are to change the status quo as far as the current treatment of such windows is concerned, it is therefore necessary to ensure that they are recognised as culturally and artistically significant works within the field of heritage conservation. Their potential protection in future will depend on this. To achieve this recognition, it is necessary to improve knowledge of the monuments by systematically recording and researching them. An almost comprehensive survey of modern stained glass has so far been carried out for the areas of North Rhine-Westphalia, Saarland, the Dutch province of Limburg and for Luxembourg. The Rhineland-Palatinate is to be the last region to be covered in 2020. It is hard to imagine that this is the work has been completed by two people. Through decades of painstaking and detailed work, Annette and Ernst Jansen-Winkeln have created a database, consisting of more than 100,000 entries, parts of which are accessible to the general public (Fig. 6).((See the webpage of Annette and Ernst Jansen-Winkeln, Forschungsstelle Glasmalerei des 20. Jahrhunderts e. V.,, accessed 16.07.2020.)) In 2016, they established their foundation, the European Academy of Stained Glass, through which they are pursuing interdisciplinary research into modern glass painting and its preservation, which would not otherwise be possible, in a private depot set up especially for this purpose.((For the Academy see its webpage, Ernst Jansen-Winkeln,, accessed 16.07.2020. The depot now houses several hundred pieces of glazing from demolished churches.))

The scientific evaluation of the collected data is still pending in most areas. In the future, such an evaluation could take place at the Heinrich-Heine-University Düsseldorf, in cooperation with our research project, which could fill gaps in the scholarship, especially with monographic studies. At present, there is very little recent scholarly literature on most of the relevant artists. From the University’s point of view, it is a good idea to make these the subject of postgraduate and doctoral research, not only revisiting existing scholarship but enriching it with new archive materials. Less well-known artists, many of whom are now very old, such as Ferdinand Selgrad (born 1927), must also be given more consideration in future. In addition, there is a lack of studies that investigate the networks involved in commissioning stained glass, including the awarding of contracts, and cooperation between artists and workshops or architects.

The challenges faced when further developing the existing material, and, in the long term, extension of the research to other regions of Germany, or to an international level, would not be new. The methodology required to conduct large-scale art-historical research the thematically comparable project of the Corpus Vitrearum Medii Aevi (CVMA). Developing and expanding research into twentieth-century stained glass would be a similar challenge, which, of course, can and must profit from the experience, both positive and negative, which the CVMA has gained through studying medieval stained glass.((This refers to all challenges, including technical, financial and in relation to personnel.))

One advantage of surveying twentieth-century stained glass, in comparison to the processing of the medieval inventories, is the incomparably better source situation. In particular, the archives of many glass workshops, some of which are extensive, are still waiting to be systematically analysed.((I am currently preparing a study on this subject. The aim is to compare several workshops in relation to the collected material (including vidimuses) and the cooperation with artists (who, when, how). The workshop owner of the renowned company Derix, in Düsseldorf-Kaiserswerth, presented a commemorative publication on its 150th anniversary. See Elisabeth Derix and Dagmar Täube (eds), Kunstzeiten. Glasmalerei ein Mosaik, Mönchengladbach, 2016.)) Art academies, and the formerly numerous schools of applied arts and crafts also provide the prospect of new discoveries.((In our forthcoming book Moderne Glasmalerei Düsseldorf (see note 2) Jürgen Wiener will, for the first time, comprehensively examine the subject of glass at the famous Düsseldorf Art Academy.)) Networks and collaborations between architects, artists and workshops could thus be made visible and enlighten us regarding a wide range of topics, from historical commissioning practices and the cooperation of the respective participants, right down to questions of costs.


In this article I have tried to outline the research project, on artistically designed twentieth-century glass windows, which initiated in the Department of Art History at the Heinrich-Heine-University Düsseldorf. The aim is to understand these windows as works of fine art and of special artistic value in the long term, in order to protect them from negligent destruction in the future. In this endeavour, it will be important to mediate between current discourses of heritage conservation and art historical interest.((Willibald Sauerländer, ‘Erweiterung des Denkmalbegriffs?’, Deutsche Kunst und Denkmalpflege 33, issue 1/2,1975, pp. 117-130.)) In Germany, a decisive significance is ascribed to the “public interest” when establishing a monument’s value.((In Germany, monument protection is the responsibility of the federal states. As an example, the Monument Protection Act of North Rhine-Westphalia begins with the first sentence: “Monuments are objects, majorities of objects and parts of objects, in whose preservation and use there is a public interest.(§1)”, March 11th, 1980.)) Without the appropriate knowledge of the works, however, such interest cannot be generated.((Thought should be given to conferences, the establishment of a suitable Internet presence and exhibitions.)) Much work still needs to be done in this area. Thus, while the creation of the inventory aims at scientific indexing this body of work, interest in the preservation of these fragile works of art, as testimonies of collective memory, must also be awakened and understood. Here too, there is still a long way to go.

I would like to express my deep gratitude to Dr Katie Harrison, not only for the opportunity to present a new research project, but especially for her patience and her help in overcoming any linguistic difficulties concerning the content in this article.


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