The tombstone of the knight Werner Letgast, who died after 1291, stands in the cloister of Walkenried Abbey in Germany. The Letgasts were a ministerialis family from Harz. There is information on the activities of the members of that family from the period 1230–1366. Werner Letgast bore the byname de Revalia, which alludes to ties with Tallinn. An undated document indicates that Letgast, the Danish viceroy in Tallinn, checked and specified the borders of the diocese and the properties of the Danish king together with the Bishop of Saaremaa Hermann de Bekeshoevede (in office 1262–1285). The terms in office of the known Danish viceroys, and similarly the mention of Werner Letgast in written sources in Germany, allow his stay in Estonia to be delimited with the years 1283–1285, or less likely 1273–1275. It is not known why and how Werner Letgast found himself in Estonia but firstly the oblique similarity of his coat-of-arms to the coats-of-arms of some leading Danish noble families, and secondly the ties between the Letgasts and the counts of Lauterberg or Lutterberg offer certain clues. For the latter reason, Werner could have been connected to Otto von Lutterberg, the Master of the Livonian Order (in office 1267–1270).

Only a few sources mention Danish viceroys in Tallinn. Thanks to the research conducted by the German researchers Jörg H. Lampe and Barbara Klössel-Luckhardt, our knowledge of Werner Letgast has been enriched notably. Nothing had previously been known about him in Estonia beyond his family name. Now we know the locations where he operated and where he is buried, we have an image of his tombstone, we know the approximate date of his death, the history of his family, his seal, and we are familiar with a number of pertinent documents.