A Church within a Church
Since at least 1259, and probably before, there has been a Parish Church of St Mary located on this site. When Truro was chosen it was assumed that the Parish Church would be completely demolished to make way for the Cathedral. However, the architect John Loughborough Pearson, argued and eventually gained permission to keep at least part of the old Parish Church. He cleverly incorporated the South Aisle of the church into his design for the new Cathedral, so that symbolically and physically the Mother Church of the Diocese has a protective arm around one of her daughter churches.
Laying the Foundation
It was with much rejoicing and celebration that two Foundation Stones were laid on 20th May 1880 by the Duke of Cornwall (later Edward VII). As well as the traditional NE corner foundation stone there was also another one laid as an act of faith. The base of a pillar made from local granite was placed in what was then the churchyard of St Mary’s. This base would eventually form one of the pillars in the Nave of the Cathedral. No one knew whether enough money could be raised to complete the building works, so it was placed there as a symbolic act of faith that one day the Cathedral would be completed.
A Gothic Revival of Victorian Vision
Truro Cathedral was the first cathedral to be built on a new site since Salisbury was started in 1220. Who else but the Victorians would have had the audacity to contemplate a building feat that colossal? For over 650 years no one had attempted to emulate the great cathedral builders of the medieval era. A massive building project in the same architectural style as the medieval cathedral builders could only have been the vision of the Victorians. They adapted the classic pointed arches of the gothic style and used modern building techniques to create the wonderful building you see around you.
source:Truro Cathedral's website