The First St Peter-le-Bailey Church dated from the 12th century. An early pictorial map depicts a single, pitched-roofed nave with a low tower at the South Western corner. The churchyard forms a roughly square area to the north of the church. On David Loggan's 1675 pictorial map of the city, the church is shown as having substantial north and south side aisles, to either side of the nave, all with pitched roofs and with a tall tower situated centrally above the nave. This proved to be a bad idea, since in 1726, the tower fell, demolishing most of the building.

The Second St Peter-le-Bailey Church was built on the site of the original church and opened in 1740. A 19th century engraving by John le Keux, shows a substantial, flat roofed rectangular building with a tower at the north west corner. An 1870 photograph by Henry Taunt depicts essentially the same building. The churchyard remained in its original position and since other buildings surrounded the plot there would have been no room to extend it. It remained in use until the middle of the 19th century, when St Sepulchre's, Osney and Holywell cemeteries opened and in 1855 new burials were forbidden at all city churches, except in pre-existing vaults. This church was demolished in 1873 as part of a road widening scheme.

The Third St Peter-le-Bailey Church was built to the north of the old church, approximately half way along New Inn Hall Street, and was opened in 1874. When St Peter's Hall was founded in 1928, this church took on the dual role of parish church and college chapel. In 1961 St Peter's Hall achieved full college status within the University and in the same year, with a dwindling population resident within the parish, it was finally merged with St Ebbe's parish and the church building became solely the college chapel, which role it still occupies today.

The Churchyard was left as a memorial garden when the church was moved in 1874. It appears that many of the gravestones were moved at that time, and in 1900 when the Tirah Memorial was erected on the site, a contemporary newspaper report in Jackson's Oxford Journal for 8th July 1900, refers to the site as "now a public garden". In photographs by Henry W Taunt, taken at the time, it is possible to discern some headstones against the north boundary wall, but the rest of the area appears to be grassed, with benches, flower beds and some mature trees.

The Tirah Memorial was the first war memorial in Oxford and was erected to commemorate the officers and men of the 2nd Battalion Oxfordshire Light Infantry who died or were killed in action on the north-western frontier of India, and elsewhere, in the period from August, 1897, to November, 1898.

The Site was renamed Bonn Square in 1974, following the building of the Westgate Shopping Centre and to commemorate the twinning of Oxford with the German City of Bonn. Apart from the introduction of a stone slab proclaiming the new name, the garden was essentially unchanged.

In 2008 Oxford City Council refurbished Bonn Square as part of a planned re-development of the Westgate Centre. The grass, which was fighting a loosing battle against heavy usage, was removed and the area was completely paved, with new lighting and street furniture. At the same time much of the area was lowered to street level. The original garden had been significantly above street level, as a result of around 700 years use as a burial ground. This work involved exposing many graves and memorials which had been hidden since 1874. Oxford Archaeology were commissioned by the council to carry out archaeological work on the site and to record all memorials found, before their subsequent re-burial below the new paving. Oxfordshire Family History Society have been given access to these records and permission to publish them here for the benefit of family historians.

A More Detailed History of the church and churchyard may be found on the following web sites:
www.british-history.ac.uk/report.aspx?compid=22821#s21
www.oxfordhistory.org.uk/burials/bonn_square/