The author describes and determines the owners of five seals from the Middle Ages that all belongs to the collection of the Ljubljana National Museum: 1. Peter Morosini, Count of Osor, the island of Cres, from the years 1205—1236, 2. Knight Gothold from Federaun near Beljak from the first half of the 14th century, 3. A Jew named Baruh who was the son of Rabbi Menahem from the 14th century, 4. Hungarian-Bohemian king Ladislav Posthumus of the Silesian knightdoms Švednice and Javor from the years 1440—1457 — in the 17th century changed to the name of Ferdinand III, and 5. the townsman of Ljubljana Wolfgang Wiser from the year 1492.