Abergavenny remained a Catholic stronghold in the years after the Reformation, and its first Catholic church built after the Reformation was on Frogmore Street.[1] This was replaced as the town's main Catholic church by Our Lady and St Michael's in 1860.[1] The construction of the church was funded by a local solicitor, John Baker Gabb, and the architect was Benjamin Bucknall.[2] Bucknall was engaged on the building of Woodchester Mansion, Gloucestershire, for another Catholic client, William Leigh, and, aged only 25, was seen as a coming man in Catholic architectural circles. Bucknall's intellectual and architectural influences were the work and ideas of Augustus Pugin – he converted to Catholicism in the year of Pugin's death – and the French Gothic Revival architect Eugène Viollet-le-Duc, with whom Bucknall was in regular correspondence.[3]
Simon Jenkins describes the church as "a bold composition of church and presbytery."[5] The interior of the church is largely unchanged since its construction with all its original Victorian furniture and furnishings intact.[1] The presbytery is similarly unspoilt.[1] The church also has "an exceptionally fine collection of medieval and later vestments".[4]