In 1423, Burgdorf acquired one half of the low court of Oberösch from Verena von Rohrmoos. Later, in the 16th century, Burgdorf bought the other half of the court from Thorberg Chapterhouse. They then combined the two halves and merged the court of Oberösch with the court of Niederösch. Oberösch shared pastures with Ersigen and Rudswil (now part of Ersigen). In 1467, Burgdorf granted the village the right to harvest timber in the Reiteneggwald. In 1525 this was expanded to include the Kriegholz and Hinterholz forests. Throughout its history it has belonged to the parish of Kirchberg.