The church notably contains the national shrine and relics of St Etheldreda, an Anglo-Saxon queen and abbess who died on 23 June AD 679 and went on to become one of the most popular of the medieval saints in England.

The opening of the London to Norwich railway line in July 1845 made it easier for Canon Quinlivan to travel to Ely and say occasional masses in a private house in the town.

[5] The parish of St Etheldreda began as a distinct and separate mission in 1890 when Fr John Francis Freeland was sent to Ely and opened the first place of worship by partitioning his lodging room to create a tiny chapel.

With numbers rising, Fr Freeland purchased ground and opened a small corrugated-iron chapel in 1892 on part of the site upon which the later St Etheldreda's church would be built.

[24] At the heart of St Etheldreda's cult was the fact that her body was found to be incorrupt, remaining whole and lifelike in the grave, rather than decomposing.

This was recorded initially by Bede in Bk 4, chp 19 of the History of the English Church thus helping her cult to become established and well known from an early date.

[25] During the medieval period the Abbeys or Cathedral churches of Durham, Glastonbury, Salisbury, Thetford, Waltham and York all claimed to have relics, or small parts of the body of St Etheldreda.

[27] There is also a small eighth-century carved frieze found in a barn wall at St John's Farm near Ely, which is thought to come from the shrine.

[33] The modern relic of Saint Etheldreda, consisting of her left hand, was found preserved in a separate reliquary, hidden in a priest's hiding hole in a house in Sussex in about 1811.

The plate itself was of a tenth-century style, suggesting that the hand had been separated from the rest of St Etheldreda's body at around the time of the tenth century.