Ælfthryth, Countess of Flanders

Ælfthryth of Wessex, also known as Elftrudis, was an English princess born around 877. She was the youngest daughter of Alfred the Great, King of England, and his wife Ealhswith. Her siblings included King Edward the Elder and Æthelflæd, Lady of the Mercians. Ælfthryth received an education alongside her brother Edward, which was uncommon for princesses of her time. Between 893 and 899, she married Baldwin II, Margrave of Flanders, and became the Countess consort of Flanders.

Ælfthryth of Wessex died on 7 June 929. Her children included Arnulf I of Flanders and Adalulf, Count of Boulogne, among others.