Not much is known about St. Tanca. She lived in Troyes, France, during the tumultuous Merovingian period. The Frankish people had been converted to Christianity during the time of King Clovis (c. 497), but by the mid-7th century the line of Clovis had weakened and France was torn by wars between petty princes and dukes. Bishops were often pawns of one or another dynastic prince and morality in the clergy was lax. It was into this atmosphere of violence and corruption that St. Tanca was born.
According to custom, Tanca was of humble origin, though her godfather was a man of modest means in the nearby town of Arcis. When Tanca was sixteen, her family was invited to a feast at the home of her godfather in Arcis. Tanca was initially left behind to keep charge of the house, but her godfather, disappointed at her absence, sent a servant to fetch her. The servant was never seen again, and the body of Tanca, with bruised face and throat cut, was found in a thicket soon after. Upon examination, her virginal integrity was intact. The conclusion was drawn that the young girl had died upon refusing the advances of her attacker, which, although based on conjecture, is probably enough.
Various embellishments surround the story; the Troyes Breviary had a fictional dialogue between her and her killer; other accounts have her as being beheaded and walking away with her head in her hands.
The real head of St. Tanca was kept in the church of Lhiutre for over a thousand years until a mob of revolutionaries attempted to destroy it in 1793, It was saved by the sister of the parish sacristan (ironically named Tanche) and restored to the Church in 1840. A commemorative cross was erected on the site of Tancra's murder in 1846 and the skull remains in the church of Lhiutre to this day. Martyred for her purity, St. Tanca is the Maria Goretti of the 7th century.
Her feast is commemorated on October 10th.