Modern Britain

In 1208, after a dispute between the rector and the priory of Holy Trinity, Aldgate (who held St Botolph without Aldgate), it was agreed that the priory should retain the tithes of Cann Hall (Leytonstone), paying the rector in grain. This agreement lasted until the nineteenth century, in spite of occasional attempts by rectors to overthrow it. Later in the original church's history, William Smith, rector from 1542, was deprived of his position in 1554 because he was married.

Humphrey Maddison, who was rector when the English Civil War began, signed the Protestation of 1641 along with his leading parishioners, headed by Sir Henry Mildmay. The ancient parish church of which he was in charge stood about twenty-one metres (seventy feet) south of the present one. Its site is still traceable in the churchyard by a line of gravestones marking the central aisle and by memorial slabs marking the chancel.

It was enlarged and renovated in 1709-1710 by Richard Allison, a Wanstead builder. The walls were raised throughout to the same height as those of the chancel and the timber west tower was replaced by one of brick 16.5 metres (54 feet) high. A west gallery was also erected. The south porch was removed and a west porch formed under the tower. However, Allison's work proved to be faulty, and in 1714 the parish vestry compelled him to repair some of it.

A drawing of the church from the south made in about 1715 shows a north aisle, a tower of three stages, and a box-like projecting sanctuary with roundheaded east window and roof pediment. By 1786, when Samuel Glasse became rector, the church had become too small for its growing parish. Having rebuilt the church in his previous parish of Hanwell in Middlesex, he immediately launched a rebuilding scheme at Wanstead. The old church was demolished in 1790.

The site of the present church of St Mary was donated by Sir James Long, Bt, from his park. Building work was completed between 1787-1790 in a classical style to the design of Thomas Hardwick. The church has not been substantially altered since it was built, but much of the stained glass was destroyed in the Second World War and not replaced. St Mary's was the only Anglican church in Wanstead until 1861 when a chapel of ease, Christ Church, Wanstead Place, was built.