In ancient Saxon mythology, Irminsul is the great sacred tree that represents the axis of the Cosmos (axis mundi), the pillar that supports the entire universe and serves as a connection point between Heaven and Earth. Its name derives from "irmin," meaning "great" or "supreme"—a characteristic associated with the god Odin/Wotan—and "sûl," which can be translated as "pillar" or "column."
Irminsul played a crucial role in the religious tradition of the Germanic peoples from ancient times. In Geismar, now a district of Fritzlar in northern Hesse, the Donar Oak (or Thor's Oak) was venerated, an ancient sacred tree of the Chatti tribe that was felled in 723 as part of the extensive Christianization movement promoted by Pope Gregory the Great and zealously carried out by Saint Boniface.
This zeal bore the condemnable traits of fanaticism. Sources recount that to impress those who had not yet converted to Christianity, Boniface sought to demonstrate the impotence of the pagan deity by destroying—with the complicity of the Frankish army—the Donar Oak without suffering any retaliation. The wood from the unfortunate tree was used to build a chapel, which was followed, half a century later, by the great cathedral dedicated to Saint Peter, which still stands in Fritzlar today.
