The Romans found good use for the Island, even though it was little more than a marshy swamp criss-crossed by tidal channels. They constructed a road and established a ferry route from the Island to the Hoo Pensinsular. The ferry - incongruously named Prince's Bridge on early maps - remained in constant use right up to the final years of the last century.
The Island and St. Mary's Creek (subsequently filled in to create the great Victorian basins we see today) - played an important part in the defence of England. Hurriedly, when an invading Dutch fleet was sighted in the summer of 1667, old ships were sunk across the creek and between St. Mary's Island and the far bank of Upnor.
It was all to no avail, for the Dutch fleet sailed round the sunken vessels, smashed through a chain stretched from one side of the river to the other, and caused such destruction to the sheltering English fleet.
From the time of the Napoleonic wars to the end of the reign of Queen Victoria, the ox-bow reaches of the river off St. Mary's Island were used to accommodate line upon line of hulked ships. These decommissioned naval vessels accommodated incarcerated hardened criminals and prisoners of war.
At the height of Victorian England, thousands of convicts were used to dig out St. Mary's Creek and construct, in its place, Basins One, Two and Three. The spoil was used to create St. Mary's Island. Completed in the 1870s, the three Basins were used by Chatham Dockyard and warships of the Royal Navy for close on 100 years. It was closed in March 1984 by the Ministry of Defence with the loss of around 7,000 jobs and left a legacy of contamination that required extensive remediation before housebuilding could even start.
In the mid 1990's, the Government announced an international competition to create a masterplan for the regeneration of St. Mary's Island, a part of the former dockyard. Of the masterplans submitted, Countryside's was the most visionary and they were chosen by English Partnerships to undertake the 150 acre residential redevelopment of the Island. A joint venture was formed between Countryside and English Partnerships, before their interest was passed to the South East England Development Agency (SEEDA) and now on to the Homes & Communities Agency (HCA).
SEEDA is responsible for the redevelopment of the remaining 200 acres known as Chatham Maritime, providing business, retail and leisure facilities to the wider community. Many of the original buildings have been retained; some sensitively converted for modern use and others retained as historical features. These include the Ship & Trades building, which has been converted into a bar, restaurant and hotel, Pump House No 5, and the Police House. The former Drill Hall has been converted into a Learning Resource Centre for the University campus.