Etheldreda, or Æthelthryth, was probably born in Exning, near Newmarket in Suffolk. She was one of four daughters of the King of East Anglia, all of whom eventually left everyday life and founded abbeys. Etheldreda made a vow of perpetual virginity, but as the daughter of a king she was expected to make a political marriage, which she did first of all in about 652 with Tondberct, chief of the South Fens. Somehow she managed to persuade her husband to respect the vow she had made. When he died in 655, Etheldreda retired to the Isle of Ely, which Tondberct had made over to her as a gift.

In 660 she remarried, again for political reasons, this time with Ecgfrith, heir to the Kingdom of Northumbria. He succeeded his father, Oswy, in 670 and, shortly after, Etheldreda became a nun. It is said that while Ecgfrith initially agreed she should continue to remain a virgin, he needed to have a legitimate heir to the throne, and in about 672 he decided to try to consummate the marriage. He even attempted to bribe Wilfrid, Bishop of York, to use his influence on the queen to convince her. This tactic failed, and the king tried to take his queen from the cloister by force. Etheldreda fled to Ely with two faithful nuns and managed to evade capture thanks, in part, to the rising of the tide.

Ecgfrith later married a second wife, Eormenburg, and expelled Wilfrid from his kingdom in 678. According to the Anglo-Saxon Chronicle, Etheldreda founded a monastery at Ely in 673, which was later destroyed in the Danish invasion of 870.

Sometimes, Father God, it is hard to go against what others expect of us and obey Your call upon our lives. Give us courage and determination to carry out our promises and fulfil Your will for us; and when we fail, please have mercy upon our weakness, forgive us and give us strength to begin again. Amen.