Although it was mentioned first in 988,[1] there had been a castle on the same site for a much longer time. The castle is situated on a rocky spur of land within a sharp bend of the Semois River.
Deville: Bouillon. In Louis Deville (edit): Les plus belles villes de Belgique. Bruxelles: Reader's Digest. 1985. 16–19. pp. ISBN 2-87101-003-X
Matthys: André Matthys: Bouillon. In Valérie Dejardin (edit) – Julien Maquet (edit): Le patrimoine militaire de Wallonie. Namur: Institut du Patrimoine wallon. 2007. 84–89. pp. ISBN 978-2-930466-20-0