The stained-glass windows of the cathedral were created over several construction phases and, with the exception of the windows of the chapels flanking the tower vestibule and the Hartmann windows, all originate from the Tiroler Glasmalerei und Mosaik Anstalt.

The oldest windows, dating back to 1868, are located in the Votive Chapel, the earliest part of the cathedral, and are characterised by bold colours and biblical motifs. Two decades later, in 1885, the high choir windows were added, thematically dedicated to the life of Mary.

Particularly striking are the windows of the nave and transept, created between 1910 and 1924. These combine sacred themes with depictions of prominent individuals and landscapes from Upper Austria. The realistic portraits of donors lend a deeply personal character to the works. Of special art-historical interest are the transept rosettes: the Peace Window illustrates virtues and works of mercy, while the War Window addresses the seven deadly sins.

The windows of the chapels flanking the tower vestibule, produced in the 1930s by the Upper Austrian glass workshop Josef Raukamp, feature geometric patterns and luminous colours.

The most recent windows in the cathedral were designed in 1994 by the artist Karl Martin Hartmann. They replace the radiating chapel windows destroyed during the Second World War. Their interplay of light, colour, and form invites contemplative reflection and stands as an artistic monument to peace.

One of the most thematically remarkable windows is located in the nave. It depicts the laying of the cathedral’s foundation stone on 1 May 1862 and masterfully unites the earthly and the sacred. Shown is Bishop Franz Josef Rudigier, initiator of the cathedral’s construction, blessing the foundation stone. Kneeling at his feet is the first cathedral master builder, Vincenz Statz, holding one of the ceremonial tools: a hammer that still exists today and was captured through photogrammetry as part of the digitisation project.

The window’s donor, the later Bishop Rudolf Hittmair, appears as a child alongside his family. In the tracery above, the Immaculata is shown as an Our Lady of Grace, with rays of grace flowing from her hands.

Unlike traditional painting, stained glass does not reflect light – it allows it to pass through. This creates vibrant colour effects that bathe the interior in a unique atmosphere. Depending on the technique used, light may be gently filtered or darkened by denser elements, resulting in striking contrasts. The windows of St Mary’s Cathedral offer a unique opportunity to trace the evolution of stained glass over more than a century.

Environmental pollution, weathering, and war damage have left visible traces on the cathedral’s valuable windows. A major restoration campaign is expected to be completed by 2030. In order to document their original condition for future generations, the stained-glass windows were recorded as ultra-high-resolution gigapixel images as part of the digitisation project.

These digital reproductions make it possible to view the windows in exceptional clarity and to discover artistic details that are often invisible to the naked eye. They offer not only a fascinating journey into the world of stained glass but also a valuable foundation for future conservation efforts.

Thanks to these digital images, the art-historical significance of the windows can now be experienced in unprecedented detail. The photographs not only document the current condition of the windows but also contribute to their long-term preservation. They provide unique access to the intricate details and symbolism of the stained glass and play an important role in protecting these cultural treasures for generations to come.