The oak tree is considered sacred to most major cultures but was held in particular high esteem to the celts the oak tree is known as the rsquofather of the woodsrsquo possibly due to its size strength and longevity the oak tree is an ancient symbol of truth courage and knowledge and was often used in spells associated with success and stability celtic weddings often took place beneath an oak tree druids belief that mistletoe was in its most sacred form when growing amongst the branche