Evidence indicates that there were settlements in the Southampton area during the Stone Age, but it was the Romans who established the first permanent settlement, Clausentum. As a trading port for two large Roman towns, Winchester and Salisbury, Clausentum acquired some importance during that time.

During their time, the Anglo-Saxons retained the use of Clausentum as a port but moved the town centre to its present location. Eventually, the settlement would change its name to Hamwic, then to Hamtum, and eventually to Hampton.

As Hampton, it was believed to have been the site of the Viking King Canute the Great's epic victory over Ethelred the Unready, the Anglo-Saxon king, in 1014. Canute the Great was eventually crowned as the King of England in Hampton. By the time the King Canute's fabled attempt to command the tide to halt took place, the settlement was already referred to as Southampton.

With the Norman Conquest in 1066, Southampton became a major transit port between the then-capital of England, Winchester, and Normany, and its prosperity was assured. The town would rise to even great prosperity in the 13th century when it became a leading port for the wool trade. In 1417, Southampton became the venue of the Wool House, a wool storage facility used for trade with Flanders and Italy. The Wool House building, now known as the Maritime Museum, still stands today.

With the dawn of the Middle Ages, Southampton's focused shifted to shipbuilding, which would become a vital industry for next succeeding centuries.

In 1338, the French raided Southampton and left devastation in their wake. Soon after, the city built its fortified walls and installed other defences that would make it the strongest fortress in all of England.

The construction of Southampton's defensive wall is a story in itself. While the town was short on finances for the construction of the wall, the town's citizens reached a compromise solution. To build the wall, the townsfolk used the exterior walls of merchant houses to form part of the defensive wall, thereby saving on costs. One such merchant wall was God's House Tower, which was England's first purpose-built artillery fortification. God's House Tower still stands today as the Museum of Archaeology.

During 1415, while King Henry V was preparing to leave Southampton for the Battle of Agincourt, authorities uncovered the so-called "Southampton Plot." The ringleaders were captured at the Red Lion pub on High Street, right within Southampton's walls. These included Richard, Earl of Cambridge; Henry Scrope, 3rd Baron Scrope of Masham; and Sir Thomas Grey of Heton. All of them were found guilty of high treason and summarily executed.

In 1623, the Mayflower departed from Southampton port carrying the Pilgrim Fathers of America. Up to that point, Southampton was the last port of call for millions of emigrants who said goodbye to the Old World to start anew in the USA, Canada, Australia, New Zealand, South Africa and elsewhere.
 
The succeeding years saw the emergence of Southampton as a popular spa town and, during the second half of the 18th century, people from all over would flock to the town to enjoy its mineral springs and bathing in the sea.

Unfortunately, the town came upon hard times during the 20th century, particularly during World War II. German bombers demolished over 600 buildings, turning them to rubble. In 1944, over three million troops and citizens departed from the Southampton docks to participate in the D-Day landings.

Southampton is also remembered as the place which launched most of the luxury liners of the time, including the Titanic, then widely regarded as a marvel and as the ship that would never sink. However, sink it did, in such a devastation manner that is has been forever immortalized by Hollywood film makers. What has gone largely unlamented is the horrible effects that this event had on the citizens of Southampton. In one school alone, as many as 140 children lost a parent, sibling or cousin when the Titanic went down.

There are now a number of memorials and museum exhibitions all across Southampton that commemorates the Titanic and its crew. A stunning 546 Southampton residents perished on the Titanic.

On the bright side, Southampton is still a vital port for ocean liners to this day, including luxury ships like the RMS QE2, the MV Oriana and the Queen Mary 2.

Southampton's emergence as England's single most important port has been a significant achievement that continues well into the 21st century.