The Manor of Millbrook dates back to Saxon times, described in charters dated 956 and 1045 as extending from Redbridge, up to Aldermoor, Shirley Warren, Lordswood, then down Hill Lane to the fishing village of Hill. The Domesday Book, compiled for Norman King William I in 1086, refers to Melebroc as being ‘held’ by the Bishop of Winchester. It covered 600 acres. In fact the land belonged to St Swithun’s Abbey – the Benedictine establishment which administered the Cathedral. After the reformation the land eventually passed into the hands of the Mill family.
Land for a new church was offered in 1871. A design by architect Henry Woodyer, in simple Early English gothic style, was approved, and the foundation stone laid on 14 November 1872 by Mrs Vaudrey, heiress to the Barker-Mill estate. The church was consecrated on 26 May 1874. The tower and spire were added in 1881-2.
The general appearance of the church has changed little over the years. Many furnishings have been donated by churchwardens and parishioners, particularly the McCarraher family. The jewel inside Holy Trinity is the chapel of SS Michael and George in the south aisle, opened in 1920 as a memorial to the men of the parish who were killed in the 1914-18 war. The exquisite altarpiece may be the handiwork of Sir Ninian Comper.
There are also memorials to parishioners lost in the Titanic disaster, all of whom lie buried in Newfoundland.