The parish church of Hackney became a sinecure rectory in 1275. This meant there was a vicar and a rector representing the parish, both positions being in the gift of the Bishop of London, and the parish served the entire area of the present London Borough of Hackney until the parish was eventually divided up in the 18th century. Many of the position holders were absentee pluralists. From the 14th century to the 17th century the church was dedicated to St Augustine. But from about 1660, the church was dedicated to St John of Jerusalem, St John the Baptist, and known as St John at Hackney, representing the links of the parish with the Order of St John of Jerusalem. The church tower was constructed as part of the early 16th century rebuilding of the church itself, commemorated by the arms of Sir John Heron carved between each arch of the nave and also placed, with those of the rector Christopher Urswick, in the chancel. Thereafter the church consisted of a chancel, aisled and clerestoreyed nave, and south-west tower. The "so-called" Rowe Chapel, properly a mausoleum, was built on the south side of the chancel in 1614 and a vestry was added on the north side. In 1741, the church measured along its north wall and across; the tower bore a vane surmounted by a crown which reached to. The walls, with fenestration of c.1500, showed a variety of materials, as they did at the time of the church's demolition, when the exterior presented 'an incomprehensible jumble of dissonant repairs, without a trace of the original building, except the windows of part of it'. In Tudor times, many members of the court used the church, including Ralph Sadleir, Thomas Sutton, Thomas Cromwell and the Earl of Northumberland. Edward de Vere, the 17th Earl of Oxford was probably buried here. Samuel Pepys visited the church in 1667, after resting at the local Mermaid Inn. He remarked on the fine organ but confessed in his diary that that which we went chiefly to see was the young ladies of the schools, whereof this is great store, very pretty – Hackney being renowned for its girls' schools at the time. The constant increasing of Hackney's population meant that galleries were added to the church, and by 1789 it was able to hold a congregation upwards of 1,000. This was still inadequate to the needs of the parish, and on the advice of architect William Blackburn, the vestry petitioned Parliament in 1790 for the church's complete rebuilding at an adjacent site to the north. Blackburn died suddenly in November 1790; James Spiller, a friend of John Soane, was chosen from six architect candidates to replace him as designer of the new church. The body of the old church was pulled down in 1798, with many of the monuments preserved in the new Church of St John-at-Hackney. The stone was sold as building material. The extent of the original church is marked by four cornerstones to the east of the Tower. The Tower remained to house the eight bells of Hackney; these were finally relocated in the new church in 1854, after the new church tower was underpinned to take the weight.
In modern times
The Tower was subsequently used as a public mortuary, and a tool shed for the gardens of St John. The Metropolitan Borough of Hackney became responsible for the maintenance of the Tower and gardens in 1912. In more recent times, the Tower was made safe in 1983, and has been used for occasional art exhibits. It is normally opened as part of London Open House each year. Since 1990, the Tower has been in the care of the Hackney Historic Buildings Trust. A grant from the Heritage Lottery Fund has made possible repairs and improvements and a permanent exhibition on the history of the Tower, and its church, is now open to the public on the last Sunday of every month. It is now possible to climb its narrow winding stairway to the roof. St John's Church Gardens, around the Tower and later church, were awarded both a Green Flag Award, and Green Flag Heritage status, in 2008.
