Osterburg Castle

The Osterburg most likely originated in the first half of the 13th century and was first mentioned in a document on March 7, 1268. It was considered equivalent to the Schleusingen office and was granted to Countess Sophia of Henneberg as a dower. The castle initially served as the seat of a Vogt, but after the main Henneberg division of 1274, when the Themar office was divided, the Vogt's seat probably moved to the town. The complicated ownership led to the Henneberg line pledging the castle to the Counts of Schwarzburg in 1359. After further sales and disputes, including sieges and devastations, the Counts of Schwarzburg confirmed their possession in 1379, but pledged the castle to the Lords of Bibra as early as 1380. They likely contributed significantly to its expansion.