It is interesting to note that New Romney is not significantly different in age from the nearby village of Old Romney. However New Romney, now about a mile and a half from the seafront was originally a harbour town at the mouth of the River Rother. The Rother estuary was always difficult to navigate, with many shallow channels and sandbanks. To make navigation easier, two large rocks, one bigger than the other, were placed at the entrance to the main channel. The names of two local settlements, Littlestone and Greatstone are a reminder of these aids. There is another likely explanation for these place names which is a result of the effects of Longshore Drift. This has had the long-term impact of dispersing shingle and sand deposites, from West to East, with heavier stones accumulating in the area known as Greatstone, whilst far smaller shingle is to be found in great quantities at Littlestone. Very fine sand is found further eastwards at neighbouring St Marys Bay.

In the latter part of the thirteenth century a series of severe storms weakened the coastal defences of Romney Marsh, and the Great Storm of 1287 almost destroyed the town. The harbour and town were filled with sand, silt, mud and debris, and the River Rother changed course, now running out into the sea near Rye, Sussex. The mud, silt and sand was never entirely removed from the town, which is why many old buildings, especially the church, have steps leading down into them from the present pavement level.

New Romney is one of the original Cinque Ports of England, although its importance declined rapidly during the fourteenth and fifthteenth centuries after the loss of the harbour.