The casket will go on tour in England and Wales
The remains of St Therese of Lisieux have arrived for their first visit to England and Wales.
She was described by Pope Pius X as "the greatest saint of modern times".
A casket containing bones from her thigh and foot will visit 28 sites in England and Wales, including Anglican York Minster and a London jail.
St Therese, a French Carmelite nun who died of tuberculosis in 1897 aged 24, came to wider attention after her autobiography was published.
The Roman Catholic Church says the relics - which have been credited with promoting healing and reconciliation - are likely to draw huge crowds during their month-long tour.
St Therese said she intended to use her time in heaven to do good on Earth, and she was considered to be an effective bridge to God.
BBC religious affairs correspondent Robert Pigott said that people prayed to her, assuming her to be in heaven, and in many cases felt their prayers had been answered.
Her remains were taken to Baghdad seven years ago in the hope of averting the Iraq conflict, and part of the relics have been sent into orbit around the Earth.
Over the next few weeks, the casket containing her bones will visit various sites, including the chapel of Wormwood Scrubs jail in London.