According to Willibald's 8th century Life of Saint Boniface, the felling of the tree occurred during Boniface's life earlier the same century at a location at the time known as Gaesmere. Although no date is provided, the felling may have occurred around 723 or 724. Willibald's account is as follows :
In the nineteenth century already Gaesmere was identified as in the Schwalm-Eder district, for instance by August Neander. There are a few dissenting voices: in his 1916 translation of Willibald's Vita Bonifacii, George W. Robinson says "The location is uncertain. There are in Hesse several places named Geismar." Historian Thomas F. X. Noble describes the location of the tree felling as "still unidentified". In the late 19th century, folklorist and philologist Francis Barton Gummere identifies the Gaesemere of the attestation as Geismar, a district of Frankenberg located in Hesse. However, most scholars agree that the site mentioned by Wilibald is Geismar near Fritzlar. In 1897 historian C. Neuber placed the Donar Oak "im Kreise Fritzlar". While Gregor Richter, in 1906, noted that one scholar considered Hofgeismar as a possible location, he himself comments that most people consider Geismar near Fritzlar as the right place. Unequivocal identification of Geismar near Fritzlar as the location of the Donar Oak is found in the Catholic Encyclopedia, in teaching materials for religious studies classes in Germany, in the work of Alexander Demandt, in histories of the Carolingians, and in the work of Lutz von Padberg. The Reallexikon der Germanischen Altertumskunde notes that for Willibald it was probably not necessary to specify the location any further because he presumed it widely known. This Geismar was close to Büraburg, then a hill castle and a Frankish stronghold.
Role in Bonifatian hagiography and imagery
One of the focal points of Boniface's life, the scene is frequently repeated, illustrated, and reimagined. Roberto Muller, for instance, in a retelling of Boniface's biography for young adults, has the four parts of the tree fall down to the ground and form a cross. In Hubertus Lutterbach's fictional expansion of the Boniface correspondence, Boniface relates the entire event in a long letter to Pope Gregory II, commenting that it took hours to cut the tree down, and that any account that says the tree fell down miraculously is a falsification of history.