It was first the site of the Franciscan Church of Greyfriars in 1225. A bigger church was built there in the 14th century said to have been the second largest medieval church in London (bigger than Wren’s replacement church). Those buried there include Isabella, wife of Edward II and Elizabeth Barton who was hanged and beheaded for treason at Tyburn after prophesying that Henry VIII would die if he dissolved his marriage to Catherine of Aragon in favour of Anne Boleyn. Her body only was buried at the church however – she is the only woman whose head was displayed on a spike at London Bridge.
This church was destroyed by the Great Fire in 1666, following which Christopher Wren was assigned to rebuild it, along with many other buildings destroyed in the fire. This church was completed in 1687 though the steeple wasn’t added until 1704.
After its destruction in the Blitz it was decided not to rebuild and the remains were given Grade I listed status in 1950. The rose garden was put in place in 1989 and has been designed to exactly match the layout of Wren’s church, with the flower beds representing the original position of the pews etc.
Interestingly the tower has been converted into a private residence and you can see an article about it here. [I have seen photos of the interior which look very impressive but I haven’t managed to re-find that website. Let me know if you do].
It’s a nice garden with an interesting history that makes for a quiet backdrop in an otherwise bustling part of the city. More photos can be found here.