What is a wheel window?
A wheel window is a circular window whose opening is divided by heavy spokes of stone, occasionally timber, radiating from a central hub out to the surrounding ring. The arrangement looks like a cartwheel, which is exactly where the name comes from.
Oculus, wheel window and rose window
The three terms form a sequence. What separates them is how far the circular opening has been subdivided.
| Type | Subdivision | Background |
|---|---|---|
| Oculus | Plain, undivided circular opening | Roman origin |
| Wheel window | Circular opening with thick, straight spokes, structural in character, no fine tracery yet | Romanesque |
| Rose window | Heavy spokes give way to fine tracery with trefoils, quatrefoils and mouchette motifs, in flower form | Gothic |
The boundary is fluid. Many rose windows simply repeat the layout of a wheel window, executed in slender tracery rather than in solid spokes. When identifying one, look less at the number of divisions and more at the thickness and treatment of the dividing members.
Period and distribution
The wheel window belongs to Romanesque architecture, roughly 1000 to 1150, and continues into the early Gothic. Its high point falls in the 12th and 13th centuries, with a clear concentration in Italy. The motif returns in the 19th century in neo-Romanesque work.
Well known examples include San Zeno Maggiore in Verona, Monza Cathedral, Santa Maria in Tuscania, Worms Cathedral and the parish church at Castle Hedingham in England. A neo-Romanesque example is the Sacred Heart Chapel in Sint-Niklaas, Belgium.
Terminology across languages
The sharp distinction between wheel window and rose window is largely a German and Dutch specialist convention. In most languages the two terms are used interchangeably.
- German: Radfenster, against Fensterrose or Rosette for the rose window.
- Dutch: radvenster, against roosvenster.
If a source describes a rose window in a Romanesque church, check the photograph. In practice it is often a wheel window.
Related terms
- Rose window
- Oculus
- Tracery
- Romanesque architecture
- Gothic
- Facade
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