St Ann Blackfriars started as a parish chapel in the Priory of the Blackfriars (Dominicans) on the banks of the River Fleet. When the Priory was dissolved by King Henry VIII in 1550, the buildings on the site were largely demolished. However, the residents still needed a parish church so a new one was established and consecrated in 1597, with the full name “The church or Chapel of St Ann, within the precinct of Blackfriars”. It is believed that the building was adapted from the old chapterhouse of the mediaeval Priory.
The site of the Old Priory of Blackfriars was a Liberty and therefore exempt from the rules of the guilds of the City of London, and so the parish of St Ann’s had an unusually large number of artists, including van Dyck, who would otherwise had to have been paid up members of the Painter Stainers. The church was destroyed in the Great Fire of London of 1666 and not rebuilt.
The parish was combined with St Andrew by the Wardrobe which stood a few hundred yards to the east, but the churchyard remained open for burials. They were only closed in 1849 and today you can still see some gravestones in what are now paved public gardens.
A vestry hall was built in 1905 to continue parish business and this building still survives. It is now the headquarters of the Ancient Monuments Society. A memorial plaque to the Blackfriars Priory stands in Church Entry Lane off Ireland Yard. The only other physical remnant of the lost church is a carved wooden statue of St Ann in the church of St Andrew by the Wardrobe
The wikipedia page for the church of St Ann Blackfriars