The Old Church.

The origins of St Helens seems to revolve around the cluniad Priory and the monastic church, built circa 1080. In 1340 a French raid landed at St Helens but was repulsed by Sir Theobald Russell. In 1346 Edward III set sail from St Helens to invade Normandy.
After the alien priories were suppressed by Henry V in 1414 the old church became the parish church. The original church eventually became unsafe, and a new church was built further inland. In 1720 a great wave destroyed the old church. At this time the entrance to the harbour was near to the church, being moved due to attempts at reclamation of the harbour which was unsuccessful due to locals removing building materials. The church was undermined by the quarrying of stone from the beach, which accounts for the large dressed blocks leading along the beach to Priory Bay. The entrance was defended by a small gun battery, which has been lost to the sea. The tower still stands to this day; the seaward side is painted as a sea mark. It is believed that Admiral Lord Nelson's last view of England was of the St Helen's seamark - HMS Victory had anchored nearby to collect drinking water, before setting sail for C'adit and participation in the Battle of Trafalgar.
Dressed stones from the walls of the destroyed church, which were soft sandstone, were found to be good for scrubbing the decks of wooden planked warships - hence the terms 'holystone' and 'holystoning the decks'.
The closest Royal commission sea fort to the island is St Helens Fort, named after St Helens.