The three giants – the main characters of this article – are the merchant houses Thomas Clayhills & Son in Tallinn, and Jacob Jacke & Co. and Hans Diedrich Schmidt in Pärnu. They can be referred to as giants for three reasons. First of all, their longevity – they operated continuously from the first half of the 18th century until around 1940. Secondly, their importance in the local economy – they shared the leading role in Estonian foreign trade over a very long period. The third and perhaps most noteworthy fact is the size and temporal extent of the archives of these merchant houses, which have survived to this day. There are about 6,000 archival records in each of the three archives, which cover more than two centuries of activity in local and international trade and commerce. The legacy of all three merchant houses is currently preserved at the Estonian National Archives in Tartu.

Closer examination brought to light that these three commerce archives are exceptional in the entire Baltic Sea region. Archives covering more than two centuries and consisting of numerous different accounting books and correspondence files can be counted using the fingers of only two hands. While early modern and 19th century merchants’ archives have been studied thoroughly and from many aspects, especially in the Scandinavian countries, there has been rather little interest in this material in Estonia. The aim of this article is to attract greater professional attention to the merchant house archives preserved in Estonia by describing their distinctive features and placing them in a broader context of international research. The article considers the activity of the merchant houses, their documentary legacy in the light of historical business practices, and possibilities for the use of this material by historians. The value of the account books of early merchants is also considered in the intermediate area between colourful ego-literature and dry yet precise accounting.

The field of research in which these archives could prove to be useful in the future is broad, extending from material culture and the history of consumption to the study of communication networks. The existence of very long series of data drawn up on a relatively uniform basis makes these commerce and trade archives unique. This directs one’s gaze once more to the possibilities of so-called serial history, l’histoire serielle. And finally, there is the neglected orientation of the history of ideas, where the epistolary practices of merchants and their accounting culture could be taken under consideration as a link in the J. Goody-like process of ‘domesticating thought’.