They are decorated with depictions of the four seasons and are the work of the famous Nuremberg engraver Georg Schwanhardt the Elder, who founded a veritable dynasty of glass artists. Georg first trained in the workshop of his father, a cabinetmaker who also specialised in making gun stocks, before he worked with the ivory sculptor Christoph Harrich.
In 1618 he moved to Prague, where he joined the workshop of Caspar Lehmann, who was the first craftsman to apply wheel engraving, previously used exclusively for gem-cutting, to glass and rock crystal.
After Lehmann’s death, Schwanhardt inherited his master’s exclusive right for wheel engraving and returned to Nuremberg, where he remained until his death in 1667.
The 9in (23cm) wide casket in the Heilbronn sale can be dated to 1650-60 and is estimated at €20,000-30,000.