Walpurgis Night (Walpurgisnacht) is a traditional religious holiday of pre-Christian origin, celebrated today by Christian as well as non-Christian communities, on April 30 or May 1 in large parts of Central and Northern Europe.
The current festival is, in most countries that celebrate it, named after Saint Walpurga, born in Devon about 710. Due to the coincidence of her holy day falling on the same day as the pagan holiday on which it was based, her name became associated with the celebrations. Walpurga was honoured in the same way that Vikings had celebrated spring and as they spread throughout Europe, the two dates became mixed together and created the Walpurgis Night celebration. Early Christianity had a policy of 'Christianising' pagan festivals so it is perhaps no accident that St. Walpurga's day was set to May 1.
Historically Walpurgisnacht is derived from various pagan spring customs. Bonfires were built to keep away the dead and chaotic spirits that were then widely believed to walk among the living. This is followed by the return of light and the sun as celebrated during May Day, although bonfires and witches are more closely associated with Easter (especially in Ostrobothnia, Finland) and bonfires alone with midsummer in the rest of Finland.
Saint Walpurga was a niece of Saint Boniface and, according to legend, daughter of St. Richard, a Saxon prince. She travelled with her brothers to Francon i a, Germany, and became a nun in the convent of Heidenhei m , Bavaria, which was founded by her brother Willibald. Shortly after moving the mortal remains of her brother, Saint Winibald, Walpurga died of an illness on 25 February 779. She is therefore listed in the Roman Martyrology under 25 February. So that she might be buried beside Willibald, her relics were transferred on 1 May, and this date remains associated with her in the Finnish and Swedish calendars .
In Estonia, Volbriöö is celebrated throughout the night of April 30 and into the early hours of May 1, where May 1 is a public holiday called "Spring Day" (Kevadpüha). Volbriöö is an important and widespread celebration of the arrival of Spring in the country. Influenced by German culture, the night originally stood for the gathering and meeting of witches. Modernly people still dress up as witches to wander the streets in a carnival-like mood.
The Volbriöö celebrations are especially vigorous in Tartu, the university town in Southern Estonia. For Estonian students in student corporations (fraternities and sororities), the night starts with a traditional march through the streets of Tartu, followed by visiting of each others' corporation houses throughout the night. The following day (May 1) is known as Kaatripäev (Hangover Day, derived from the German word 'Kater' meaning 'Hangover').