What is "walpurgis night"

1820, from German Walpurgisnacht, witches' revel, especially on the Brocken in the Harz Mountains, on May-day eve, literally "the night of (St.) Walpurgis," from Walburga, English abbess who migrated to Heidenheim, Germany, and died there c.780; May 1 being the day of the removal of her bones from Heidenheim to Eichstädt.

Walpurgis Night is the English translation of , one of the Dutch and German names for the night of 30 April, so called because it is the eve of the feast day of Saint Walpurga, an 8th-century abbess in Francia. In Germanic folklore, Walpurgisnacht, also called (; literally "Witches' Night"), is believed to be the night of a witches' meeting on the Brocken, the highest peak in the Harz Mountains, a range of wooded hills in central Germany between the rivers Weser and Elbe. The first known written occurrence of the English translation "Walpurgis Night" is from the 19th century. Local variants of Walpurgis Night are observed across Europe in the Netherlands, Germany, the Czech Republic, Slovenia, Sweden, Lithuania, Latvia, Finland and Estonia.