"St. Patrick's Cathedral, Armagh"

By 1854 there had been a revolution in ecclesiastical architectural taste in Ireland. The Perpendicular Gothic style of the sixteenth century had fallen from favor and earlier Medieval Gothic had become more popular.

The new architect,  McCarthy, did not wish to continue to build in the now unfashionable Perpendicular Gothic used by his predecessor. His solution was to start building a Decorated Gothic Cathedral of the fourteenth century on top of the purportedly sixteenth century foundations and walls.