Wenceslaus I of Bohemia
The first written mention of Osek is from 1240 from a deed issued by the King Wenceslaus I of Bohemia to the monastery of Plasy, where a man by name of Budivoj of Osek is referred to. Monastery in Plasy was founder of Osek. The village was dominated by small Gothic keep, rebuilt into a Renaissance castle in the 2nd half of the 16th century.