The Codebook of Willem Six van Oterleek: Dutch Diplomatic Intelligence from Saint Petersburg between 1806-1810

Abstract

Between 1806 and 1810, Willem Six van Oterleek served as diplomatic representative of the Netherlands in Saint Petersburg, Russia. During these years, van Oterleek kept his Minister of Foreign Affairs informed as fully as possible about political developments, information he received from other diplomats and the couleur locale from his posting in Saint Petersburg. This sensitive communication was to be kept secret and was therefore sent in code. These coded messages and the accompanying codebook that was used to protect them survived in the Dutch National Archives. This article will explore this codebook, analyse code usage and decode the secret messages to present a unique peek behind the curtain of the diplomatic developments and intrigues of those days.