Gijsbert Heeck (1619-1669) was a medicinal specialist with the Dutch East India Company (VOC). His journal is based on the daily notes he made during his third trip to the East. This volume carries the selections from his journal that deal with Siam, accompanied by the original Dutch text.

Heeck reveals how Siamese authorities reacted to a violent confrontation between the Dutch and the Portuguese. He gives a detailed description of the Dutch lodge in Ayutthaya, and also bits of information on the relationships of local Dutch men with indigenous women. His record of villages along the Chao Phraya River specializing in the making of coffins, preparing and selling firewood, painting, and producing earthenware, signal the existence of a complex economy in this part of Siam. Compared with the other seventeenth-century descriptions primarily of the landscape, Heeck's journals provide more information on population, scenery, traffic, trade, and religious establishments than all the others combined. He also provides a unique early perspective on local social arrangements and political intrigue, and on interactions between the Dutch and the locals.