Hayling Island is part of a drowned landscape and is, like several other islands around the English coast, a "holy" island. The first Celtic wooden shrine was built in the centre of the north of the island. That shrine was replaced by a Roman stone temple. The first Christian presence was circa 870AD in the form of the base of a Saxon cross now used as the font. The first Church, dedicated to All Saints, was built on land, now inundated by the sea, but still identified as Church Rocks. A chapel of ease was built in North Hayling in 1150 on the site of St Peter's Church and the present site of St Mary's was built from 1253 onwards.

St Mary's Key Dates:-
1253 Building started
1325 Inundation of the South half of the island
1569 Repairs to the West Wall and Building of the Porch
1868 Restoration of the Nave Greatest Window
1889 Earthquake
1892 Further restoration and repair after the earthquake
1893 Repair of the Chancel Roof
1970 Plaster stripped from the walls
1987 Spire repaired after Great Storm