It was one of the Cinque Ports and still has many original medieval buildings, including several listed public houses and gates in the old town walls, churches, almshouses and the White Mill. While once a major port, it is now two miles from the sea, its historic centre preserved.
In 1028 King Canute granted a charter to the monks of Christ Church, Canterbury to operate a ferry across the river and collect tolls.
In 1192 Returning from the Third Crusade, Richard the Lionheart was jailed by the Holy Roman Emperor Henry VI. Henry released Richard in February 1194. On 13 March 1194, Richard landed at the port of Sandwich and came back to England.
The coat of arms of Sandwich is Per pale Gules and Azure three demi-Lions passant guardant in pale Or conjoined with as many sterns of demi-Ships Argent,. It is one of the earliest heraldic examples of dimidiation, an early method of combining two different coats of arms, which in this case combines elements of the Arms of England (1198-1340), Gules three lions passant guardant Or langued and armed Azure, and of the Arms of the Cinque Ports, Azure three ships Or.
Before Sandwich became a Cinque Port, the ancient Saxon town of Stonar, located on the bank of the Wantsum estuary, but on the opposite side of the mouth of the River Stour, was already well established. It remained a place of considerable importance until it disappeared almost without trace in the 14th century. The ruins of the major Roman fort of Richborough are close by. It was the landing place of the Roman invasion of Britain in AD 43. In 2008, an archaeological dig proved that this was a defensive site of a Roman beachhead, protecting 700 metres of coast.
The Port of Sandwich is no stranger to odd events in English history. It was here in 1255 that the first captive elephant was landed in England, The prize beast arrived at Sandwich quayside, delivered as a gift to the English monarch Henry III, from the French king, and was then taken on foot to the king's zoo at the Tower of London. The journey through Kent is reported to have proceeded without incident, except when a bull in a field adjacent to the roadside took umbrage to the great beast passing and attacked it. In one move the animal was thrown by the elephant and killed outright.
On 28 August 1457, after four years of uneasy peace in England the king presided over a wasting realm, with feudal barons lording over the population of the north and the west of the realm. The French took advantage of the situation by sending a raiding party to Kent, burning much of Sandwich to the ground. A force of around 4,000 men from Honfleur, under the command of Marshal de Breze came ashore to pillage the town, in the process murdering the mayor, John Drury. It thereafter became an established tradition, which survives to this day, that the Mayor of Sandwich wears a black robe in mourning for this ignoble deed.
Sandwich was later to gain significantly from the skills brought to the town by many Flemish settlers, who were granted the right to settle by Queen Elizabeth I in 1560. These settlers, brought with them techniques of market gardening, and were responsible for growing the first English celery,which was already and still very popular in Flanders. Elizabeth I granted 25 Flemish families permission to live in Sandwich and St Peter became the "Stranger's Church" in 1564 when the plague came to the town in an effort to halt the spread of the disease. The 1661 tower collapse was repaired by the Flemish community and the distinctive tower reflects their work. The Huguenot refugees also brought over Flemish architectural techniques, that are now as much a part of Kent as the thatched cottage. People still can see the difference in English (lower section) and Flemish (upper section) of the tower. In addition techniques of silk manufacture were imported, enhancing the Kent cloth industry.
In World War One, Sandwich was important as a transit location for troops heading to Ypres.
In 1980 Jean Barker was made Baroness Trumpington of Sandwich.
In 2014 an original copy of the Magna Carta, issued in 1300, was found in conjunction with a copy of the Charter of the Forest. It was only the second time in history that the two documents have been found together.