The Roman fort at Richborough is one of the most important Roman sites in Britain. It was in use for the entire duration of the Roman occupation of Britain from AD43 to around AD410 when Roman rule came to an end as the forces left to defend Rome from attacks from Goths and Vandals.
The Roman landings of AD43 were either actually here at Richborough (then on the coast south of the then truly insular Isle of Thanet) or very nearby.
At this time, Richborough itself was virtually an island cut off at high tide. A natural harbour was formed by the large shingle banks at Stonar to the east.
Initially simply a fort, over the next few decades it expanded into town and port. First a supply depot was created around AD60, laid out in the customary grid pattern of Roman settlements. Granaries and store houses were created to house the goods for onward trade.
In AD85 much of the site was levelled to create the new town centred around a huge monumental arch, a literal and metaphorical gateway to Britain. This arch was truly monumental in scale; a 30' (10m) deep block of concrete has been discovered by excavation that served as the foundations for it. It is thought that it was about 85' (25m) tall and contained something like 40,000 tons of stone and filling materials, then clad in white marble brought all the way from northern Italy. Sadly nothing remains of this remarkable structure save the aforementioned foundations.
By the C2nd AD this town had flourished and covered something like 50 acres - well beyond the walls of the site that we now see - as these were created later (see below). Around 250AD trouble was brewing in the form of Anglo-Saxon and Jutish raiders. The army returned in force; part of the centre of the town around the now apparently rather dilapidated monumental arch were cleared of buildings and three large defensive ditches were created around it.
The new defences were strengthened, such that by AD275, the walls that we now see were built around the triple ditches, encompassing an area of about 8 acres. Civilian dwellings would have been mainly outside the walls, with the more important buildings and prestigious dwellings inside the protection of the new fortifications.
It seems the town then settled down again, partly due to the actions of the Roman admiral Carausias who it seems was successful in stopping the pirate raids in the late C3rd.
A huge number of coins (about 56,000) have been found at Richborough, and almost half of these date from the period between 288 and 402 suggesting that this was the heyday of the town and port's commercial activity.
The town was abandoned by the Romans, as mentioned earlier, around AD410 and its decline after that was probably quite rapid, though the remaining Romano-British and invading peoples probably both used the site, and quarried stone from it for use in other buildings.
One final interesting discovery was that of a font from an early Christian church (see TR3260 : Richborough Castle
Roman Fort - remains of font) an example of Christianity in Britain a number of centuries before Augustine's arrival and its reintroduction.