The crypt which sat (and still sits today) beneath the 11th-century church was the first arched crypt found in any church in London. The 'le-Bow' in the church’s name derives from those arches, and the Latin name Sancta Marie-de-Arcubus bears further witness to the importance of the arched crypt.
The c.1080 building was apparently one of the earliest stone churches in London, and the second tower of that church (completed in 1512) was crowned by five lanterns, four at the corners of the tower and the fifth held aloft on flying buttresses. In the 11th century St Mary-le-Bow was known as St Mary Newchurch to distinguish it from its near neighbour St Mary Aldermary (Older Mary) which is located at the end of Bow Lane, about two hundred yards to the south of St Mary-le-Bow. The City of London in those days was London; a densely populated square mile in which tens of thousands of people lived in close proximity and in a large number of tiny wards and parishes, each having its own parish church. The emerging suburb of Westminster was a long walk from London, through fields and pastureland, with villages like Holborn as stopping points along the way.
Arising from its close relationship with the See of Canterbury,
St Mary’s served as the meeting place of the medieval Court of Arches, though a Daily Telegraph pamphlet produced in 1964 to mark the re-consecration of the church notes that 'the Court was later moved to the Sanctuary of Westminster where its successors now meet'. That temporary relocation has happily now been reversed, however, and the Court of Arches once again meets at St Mary-le-Bow today. Equally the Vicar General's court also sits at St Mary-le-Bow; every diocesan bishop in the southern province of the Church of England today receives confirmation of his election at St Mary-le-Bow and it is here also that they take the Oath of Allegiance, in the presence of the Archbishop of Canterbury, prior to their enthronement.