8,500 years ago, a chalk land bridge between Great Britain and Europe, broke down due to rising sea levels, creating the English Channel and allowing enormous amounts of shingle to be pushed by the sea to form the shingle coastline of Rye Bay.
Over the last thousand years, there have been many events that have shaped the area that we see today:
| 1287 | Great storms washed away a shingle bar with Old Winchelsea on it (near today’s river mouth) and the river Rother was diverted from New Romney to enter the sea at Rye Harbour |
| 1542 | A reforming shingle spit was the location for Henry VIII to complete Camber Castle to protect the prosperous hilltop towns of Rye and (New) Winchelsea |
| 1637 | Camber Castle was abandoned because land had built up in front of it |
| 1806 | During the Napoleonic War, the Royal Military Canal and several Martello Towers were built. Tower no. 28 at Rye Harbour was built near the shore |
| 1854 | A railway was opened from Rye to Rye Harbour |
| 1865 | A lifeboat house was built on the shore at the closest accessible point to Rye Harbour |
| 1860s | A tar distillery was set up on Rye Harbour road |
| 1928 | The Mary Stanford Lifeboat was launched from the boathouse on the shore and all 17 crew were lost on 15th November |
| 1932 | Serious flooding by sea at Winchelsea Beach. The breach was not repaired until June 1933 |
| 1930s | Shingle was extracted from Flat Beach for the production of blocks to create Dover Harbour |
| 1940s | Another threat of invasion required the shore to be fenced and mined while several machine gun blockhouses were built overlooking the sea. Anti-aircraft guns were placed on the Martello Tower and Camber Castle and a “starfish decoy” town was created near the castle with a Stanton Shelter to operate it |
| 1946 | The concrete road to the shore was built and shingle recycling started with lorries moving thousands of tonnes of flint stones westward each year against longshore drift. This road stopped the sea from flooding land near the river |
| 1956 | The first designation as a Site of Special Scientific Interest |
| 1970 | Rye Harbour Nature Reserve was established by a group of local partners |
| 1972 | The first birdwatching hide was built, overlooking Ternery Pool |
| 1973 | The Friends of Rye Harbour Nature Reserve was established for individuals to provide funding and volunteers for the Nature Reserve |
| 1978 | The larger islands were created at Ternery Pool. Electric fencing was used to protect nesting Little Terns, An Information Kiosk was opened in the car park |
| 1986 | The Friends bought Watch Cottage as a base for the warden |
| 1992 | Sussex Wildlife Trust (SWT) purchased Castle Water with support from the Friends |
| 1999 | Designation of the Dungeness to Pett Level Special Protection Area |
| 1999 | The Friends leased Lime Kiln Cottage and opened it as an Information Centre manned by volunteers |
| 2003-6 | SWT created a 20ha reedbed at Castle Water |
| 2005 | Designation of the Dungeness Special Area of Conservation |
| 2006 | The Environment Agency completed the secondary sea defence bank which created several new saline lagoons and wet grassland with many new ponds |
| 2011 | Management of the Nature Reserve was transferred to SWT from East Sussex County Council and the Environment Agency leased the southern part of the reserve to SWT. The Environment Agency completed works to allow the sea back into two fields near the river, recreating 20 ha of saltmarsh and also a new footpath to view it |
| 2021 | The new Discovery Centre was opened |