This happened in the 12th century and the girl who took such desperate action was Christina, the founder of a convent at Markyate.

Her story is to be told by a former vicar of Markyate, the Revd Michael Crow, during a pilgrimage tour by river from Moscow to St Petersburg in May.

He was interested in history, especially medieval times, and has lectured on Christina and her book, the St Albans Psalter.

Born in Huntingdon, Cambridgeshire, around 1095, Christina took a vow of chastity as a young girl during a visit to St Albans Abbey. Her parents tried to force her into marriage and she ran away, taking refuge first in Flamstead and eventually in Markyate under the care of Roger, a hermit and monk and also a deacon of the Abbey.

According to records it was during the period in hiding that she experienced her first visions of the Virgin Mary and Jesus Christ.

Her parents seem to have had some success in achieving their ambition because the article in the current Diocesan news and information bulletin about the pilgrimage says that "after a protracted process" Christina's husband freed her from marital obligations and she was able to emerge from hiding.

Over the years her reputation for holiness and visionary gifts became widely known and other women joined a community around her at Markyate in land left to her by Roger. The community received considerable support from the then Abbot of St Albans, Geoffrey de Gorham. Christina formally announced her vocation as a nun in about 1130.

The Revd Crow worked as a parish priest in the Diocese of St Albans for 37 years and now, in retirement, lives with his wife Jean in Exeter where he is licensed to officiate in that diocese.

He is leading the Moscow to St Petersburg pilgrimage with retired civil servant John Coleman, who took up the specialised craft of iconography in 1995 while living with the Franciscan Brothers of Hillfield Friary in Dorset.

Strict rules, set down in 787 AD, apply to icons, which must be "written" and not "painted" to avoid making idolatrous images. They tell stories from the Bible and the lives of famous saints in pictures, and it is said that they are to be "read" and not simply looked at as people look at an ordinary picture.

Saint Christina is the subject of one of his icons.

The Revd Crow can be contacted on 01392 424804.