|Intro||Heiress of Garding and by marriage Duchess of Lüneburg|
|Death||November 22, 1233 (Lüneburg, Lüneburg, Lower Saxony, Germany)|
Princess Helena of Denmark (c. 1180 – 22 November 1233 in Lüneburg) was heiress of Garding and by marriage Duchess of Lüneburg. She is the ancestress of all later Guelphs.
Helen was the youngest daughter of Valdemar I of Denmark and Sophia of Minsk. She was the sister of the Kings Canute VI and Valdemar II and Queen Ingeborg.
In the summer of 1202 in Hamburg, Helena married Duke William of Lüneburg (1184–1213), so she became the daughter-in-law of Henry the Lion of Saxony and his English wife Matilda. Helena and William had one son, the future Duke, Otto I, The Child of Brunswick-Lüneburg (1204–1252). After the early death of her husband, Duke William, in 1213, his brother Emperor Otto IV took over the reign of Lüneburg, as regent for William's son Otto the Child. Otto was appointed heir of the allodial property of the Guelphs by his uncle Henry the Elder.
Duchess Helene died in 1233 and was buried in the Benedictine monastery of St. Michael in Lüneburg.