For a long time, up to the 1970s, it was believed that, in the Middle Ages, glass objects were both expensive and rare almost everywhere north of the Alps. Old research was based on written sources where glass, like ceramics, is mentioned very rarely. For example, the earliest survived reference to glass objects in Finland dates from as late as 1549. New and more careful archaeological excavations have revolutionised the view of glass usage, first in Central Europe and now also in the northern regions. Glass objects were not only treasures of the nobility and the wealthiest churchmen, but were also seen at the tables of town burghers.
