Walpurgis Night is a holiday celebrated on April 30 or May 1, in Germany, Finland, Sweden, Estonia, Lithuania, Latvia, Romania, and the Czech Republic .
The festival is named after Saint Walburga (known in Scandinavia as "Valborg"; alternative forms are "Walpurgis", "Wealdburg", or "Valderburger"), born in Wessex in 710. She was a niece of Saint Boniface and, according to legend, a daughter to the Saxon prince St. Richard. Together with her brothers she travelled to Franconia, Germany, where she became a nun and lived in the convent of Heidenheim, which was founded by her brother Wunibald.
Walburga died on 25 February 779 and that day still carries her name in the Catholic calendar. However she was not made a saint until 1 May in the same year, and that day carries her name in the Swedish calendar.
Historically the Walpurgisnacht is derived from Pagan spring customs, where the arrival of spring was celebrated with bonfires at night. Viking fertility celebrations took place around April 30 and due to Walburga being declared a saint at that time of year, her name became associated with the celebrations.
Walburga was honored 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.