kotbåge

A kotbåge, also known as a *knot arch* or *knot vault*, is a type of architectural vault found primarily in Scandinavian and Baltic medieval construction. The term derives from the Swedish *kot* (meaning "knot") and *båge* (meaning "arch"), reflecting the way the vault’s ribs appear to converge in a central knot-like pattern. This design was particularly common in churches, barns, and other structures built between the 12th and 16th centuries, particularly in regions such as Sweden, Norway, and parts of Estonia and Latvia.

The kotbåge is characterized by its ribbed stone or brick vaulting, where the intersecting ribs meet at a single point, creating a distinctive geometric pattern. Unlike the more common ribbed vaults found in Gothic architecture, the kotbåge often features simpler, more organic rib shapes that resemble intertwined knots or braids. This style was well-suited to the local materials and construction techniques of the time, allowing for durable yet visually striking structures without the need for elaborate scaffolding or skilled labor.

One of the most famous examples of kotbåge architecture is found in the medieval churches of the Swedish island of Gotland, particularly in the Romanesque-style buildings of the 12th and early 13th centuries. These vaults were not only functional, providing structural support, but also served as decorative elements, enhancing the aesthetic appeal of the buildings. The kotbåge’s popularity declined with the rise of Gothic architecture in the later Middle Ages, though it remains a distinctive feature of Scandinavian medieval heritage.

Today, kotbåge vaults are studied as important examples of regional architectural innovation. Their unique design reflects the adaptation of foreign architectural ideas—likely influenced by Norman or early Gothic styles—to local conditions. Preservation efforts continue to highlight these structures as cultural landmarks, offering insights into medieval construction methods and artistic expression in Northern Europe.