(from FARMER, David: _The Oxford Dictionary of Saints_, 3rd ed. OUP, 1992.)
Etheldreda restored an old church at Ely, reputedly destroyed by Penda, pagan king of the Mercians, and built her monastery on the site of what is now Ely Cathedral. After its restoration in 970 by Ethelwold it became the richest abbey in England except for Glastonbury.
Etheldreda died c.680 from a tumour on the neck, reputedly as a divine punishment for her vanity in wearing necklaces in her younger days; in reality it was the result of the plague which also killed several of her nuns, many of whom were her sisters or nieces. At St Audrey's Fair necklaces of silk and lace were sold, often of very inferior quality, hence the derivation of the word tawdry from St Audrey.
17 years after her death her body was found to be incorrupt: Wilfred and her physician Cynefrid were among the witnesses. The tumour on her neck, cut by her doctor, was found to be healed. The linen cloths in which her body was wrapped were as fresh as the day she had been buried. Her body was placed in a stone sarcophagus of Roman origin, found at Grantchester and reburied.
Her shrine was destroyed in 1541, but some relics are alleged to be in St Etheldreda's Church, Ely Place, London (where the bishops of Ely formerly had their London residence). Her hand, which was discovered in a recusant hiding place near Arundel in 1811, is claimed by St Etheldreda's RC church at Ely.