The Thames along the Saxon Shore Way is more than ½ a mile wide, and has a depth, at low water, of about 48 feet; and it begins to expand below, forming there the Hope, the last of its many reaches; yet it is supposed, by some writers, for reasons of merely fancied changes of depth of channel, to have been forded at Hinham, about a mile lower down, in the yeare 43, by Aulus Plautius, the lieutenant of Claudius. Throughout its history, the proximity of the marsh to the European mainland has meant that the areas has been in the front line whenever invasion has threatened. In 892 AD the Danish fleet of 250 ships sailed right into the Rother and took the fortress at Appledore (allegedly built by King Arthur), which they destroyed. The Marsh became the property of the Priory of Canterbury in the 9th century, who granted the first tenancy on the land to a man called Baldwin, sometime between 1152 and 1167. The place belonged to Bishop Odo; and passed to successively the Cremilles, the Uffords, St. Mary's abbey, and the Earls of Darnley.

The most significant feature of the Marsh is the Rhee wall (Rhee is a word for river), forming a prominent ridge among walls not built in Roman times. This feature was extended in three stages from Appledore to New Romney in the 13th century as a waterway. A village and parish in Tenterden, Appledore in Kent stands on a branch of the river Rother to once was a seaport, on the quondam estuary of the Rother; and it was assailed by the Danes in the time of King Alfred, and by the French in 1380. The living is a vicarage in the diocese of Canterbury; and includes the curacy of Ebony. Sluices controlled the flow of water, which was then released to flush silt from the harbour at New Romney. In 1250 and in following years, a series of violent storms broke through the coastal shingle banks, flooding significant areas and returning it to marsh, destroying the harbour at New Romney, and in 1287 finally destroying the port town of Old Winchelsea (now located some two miles (3 km) out in Rye bay), which had been under threat from the sea since at least 1236. By the 14th century much of the Walland and Denge Marshes had been reclaimed. Ultimately the battle was lost, the harbour silted up and New Romney declined in importance, however, the Rhee kept part of the old port open until the 15th century. From 1564 the health of the marsh population suffered from malaria, then known as ague or marsh fever, which caused high mortality rates until the 1730s. (geographic level 5 Higher-level District)

A congeries of elevations in Sussex called the Forest Ridge, commences near the east end of the South Downs; spreads east-north-eastward and northward to the boundary with Kent; and rises, at the centre, to an altitude of 804 feet. A low-wooded tract, the Weald of Sussex, with diversified surface, and fringed or engirt with uplands, forms all the area north of the South Downs and west of the Forest Ridge. In Sussex the chief streams are the Rother, the Cuckmere, the Ouse, the Adur, the Arun, and the West Rother. Lower greensand rocks occupy about three-fourths of the entire area, inward from the N and the E boundaries. Sussex contains 317 parishes, parts of 4 others, and 5 extra-parochial tracts. By the 16th century the course of the Rother had been changed to its channel today; and most of the remainder of the area had now been reclaimed from the sea. The shingle continues to be deposited. As a result all the original Cinque Ports of the Marsh are now far from the sea. Dungeness point is still being added to: although (especially near Dungeness and Hythe) a daily operation is in place to counter the reshaping of the shingle banks, using boats to dredge and move the drifting shingle. The marsh has since become covered by a dense network of drainage ditches and once supported large farming communities.

In England parishes very broadly correspond with villages.