Rugendas was a member of a prominent family of clock and sundial makers in Augsburg. This watch has long been known as the Great Ruby Watch for its eighty-five clear rubies. Its cover is a fine example of the florid style of Augsburg goldsmiths’ work that was in vogue from about 1660 to 1680. The enamel of the inside cover and the dial are equally fine examples of Augsburg work.