Mildred (Old English Mildþrȳð, 'mild strength') was the daughter of King Merewalh of the Magonsæte and St. Eormenburh of Kent — placing her in the most extensive 7th-century English royal-saint kindred (her sisters were St. Mildburh of Wenlock and St. Mildgyth, the famous 'three royal Anglo-Saxon women saints' of the late 7th century).
She was educated at the monastery of Chelles in Frankish Gaul (the foundational royal Frankish women's monastic centre under Abbess Bertila), where she resisted an attempted forced marriage to a nobleman who tried to force her against her will (per her late-7th-century Vita, she was burned in an oven by her would-be husband but emerged unharmed — one of the most vivid early Anglo-Saxon hagiographical episodes).
She returned to Kent and entered the double monastery at Minster-in-Thanet, founded by her mother Eormenburh around 670 on lands granted by King Egbert of Kent. She succeeded her mother as abbess around 694 and governed Minster for nearly forty years until her death around 732.
Her reputation for gentleness, mercy, and care for the poor made her the foundational beloved royal saint of medieval Kent. In 1035, her relics were translated to St. Augustine's Abbey, Canterbury, where her shrine became one of the principal Kentish pilgrim destinations.