The great stoneware jars of Borneo, which form the treasured heirlooms (pusaka) of many Bornean households, are very much in vogue amongst Western and South-East Asian collectors who today help to sustain a trade in them which has been one of great significance and profit in the region forcenturies. However, suprisingly little is known about these jars, their significance or their provenance. In this study, for the first time the secrets and mysteries of these ceremonial jars are unravelled. The jars are studied by means of reference to the modes of production, to the literature onthe subject (particularly that from the nineteenth century), and to archaeological finds. From this three angled-approach a composite picture emerges which shows their origins, establishes a classification of jar-types, and reflects many facets of popular Bornean culture as revealed by the trade injars, their history and the lore that surroundes them.The text is accompanied by 32 colour illustrations and more than 100 illustrations in black and white of Bornean jars to be found in various museums, in particular the excellent Brunei and Sabah museum collections, covering specimens ranging from the ninth to the twentieth centuries.Barbara Harrison developed her knowledge of and interest in Bornean jars whilst working with her husband, the late Tom Harrisson, in Sarawak. She was formerly the Director of the Princesshof Museum, Leeuwarden, The Netherlands.