A great many graves from the Early Middle Ages have been found in the row of dunes along the coast of Holland. In 1909 and 1910, J.H. Holwerda, Director of the National Museum of Antiquities, carried out excavations in a Frankish burial ground at Katwijk, at the site known as Klein Duin. ‘A number of human skeletons’ had already been discovered there in 1906. Some of the 80 graves contained glass tumblers. They were blown from light-green, relatively thick glass, and were therefore still intact. These drinking glasses were at the head ends of men’s graves, which also contained swords. This kind of glass was originally called a ‘tumbler’ because it could not stand up: once it was filled with wine, you had to empty the glass or pass it on.