The article shapes a new approach towards the oldest lexicographic monuments of the Baltic languages: Elbing vocabulary and the so called Simon Grunau's vocabulary. Both manuscript sources are associated with Hanseatic utilitarian bilingual lexicographic tradition and are thoroughly compared with the so called "Russian books", i.e. transcripts of Low German-Russian vocabularies and phrase-books compiled by young Hansa men, the so called sprakelerere, for practical language learning and business purposes.
A conclusion is made that German-Prussian vocabularies and phrase-books became relevant, i.e. they were compiled, soon after Elbing was granted Lübeck law and German merchants and colonists arrived at the new market to make profit. The Elbing vocabulary and Grunau's vocabulary are closely linked with Elbing; the influence of the Hanseatic lexicography is also seen in the Polish-Yotvingian vocabulary.
The vertical reading of Grunau's vocabulary enables us to reconstruct the mercantile phrase-book, i.e. the functional style which has not yet been grasped in the Baltic corpus - the German-Prussian mercantile sociolect of the second half of the 13th century. There were no respective preconditions for the formation of lexicography on the basis of the Lithuanian language in the 13th century (due to the limited geography of the spread of Hansa merchants).