The name Romsey is believed to have originated from the term Rūm's Eg, meaning "Rūm's area surrounded by marsh".
What was to become Romsey Abbey was founded in 907. Nuns, led by Elflaeda daughter of Edward the Elder, son of Alfred the Great, founded a community — at his direction — in what was then a small village. Later, King Edgar refounded the nunnery, about 960, as a Benedictine house under the rule of St. Ethelflaeda whose devotional acts included chanting psalms while standing naked in the cold water of the River Test.
The village swelled alongside the religious community.
The Vikings sacked Romsey in 993, burning down the church. But the village recovered, and the abbey was rebuilt in stone in about 1000. The religious community flourished as a seat of learning, especially for the children of the nobility. A market was established outside the abbey gates.
The Normans built the large current abbey that dominates the town (between c. 1120 and 1140) on the site of the original Saxon church. By 1240, 100 nuns lived in the convent.
King Henry I granted Romsey its first charter. This allowed a market to be held every Sunday, and a four-day annual fair in May. In the 13th century, Henry III permitted an additional fair in October.
The lucrative woollen industry appears to have powered Romsey's growth during the Middle Ages. Wool was woven and then fulled or pounded with wooden hammers whilst being washed. It was dyed, and then exported from nearby Southampton.
Romsey continued to grow and prosper until plague struck the town in 1348-9. The Black Death is thought to have killed up to half of the Romsey's population of 1000. The number of nuns fell as low as 19. Prosperity never returned to the abbey. It was finally suppressed by Henry VIII during the Dissolution of the Monasteries in 1539. Many religious buildings were destroyed during this time, but the abbey was saved from demolition because part of it was a parish church for the people of Romsey. The town purchased the abbey from the Crown for £100 in 1544. Ironically, the part of the abbey that had saved the abbey, the church of St Lawrence, was then demolished.
By the mid-16th century Romsey's population was about 1,500; its woollen and tanning industries fuelled growth. On 6 April 1607 King James I granted the town a charter making it a borough. This gave official status to an informal local government that had been running the affairs of the town since the Dissolution of Romsey Abbey in 1539. Romsey could now have a corporation comprising a mayor, six aldermen and twelve chief burgesses, with a town clerk for 'office work'. Furthermore, there was to be a local law court under a Court Recorder, assisted by two sergeants-at-mace. Over all, was the prestigious position of High Steward, the first of whom was the Earl of Southampton. (Lord Brabourne, grandson of Lord Mountbatten of Burma, is the current High Steward.)
Romsey changed hands several times during the English Civil War. Both Royalist and Parliamentary or Roundhead troops occupied and plundered the town. Royalists remained in control of the borough until January 1645.
The town's woollen industry survived until the middle of the 18th century, but was beaten by competition from the north of England. But new fast-growing enterprises soon filled the gap with brewing, papermaking and sackmaking, all reliant upon the abundant waters of the Test.
By 1794 a canal connected Romsey to Redbridge — at the mouth of the River Test — and Andover. Industry continued to grow. Romsey was a reasonably large town for the early 19th century: its population was 4,274 in the first census of 1801, compared with just 8,000 for Southampton, but expansion slowed, despite the railway arriving in 1847. In 1851 Romsey's population was 5,654 and was almost the same half a century later (5,597 in the 1901 census).
Lord Palmerston, the 19th-century British Prime Minister, was born and lived at Broadlands, a large country estate on the outskirts of the town. His statue stands in the Market Place outside the Town Hall.
Romsey was famous for making collapsible boats during the 19th and early 20th centuries, invented by the Rev. Edward Lyon Berthon in 1851. The Berthon Boatyard in Romsey made the boats from 1870 until 1917. They were used as lifeboats on ocean-going liners, including the Titanic.
Broadlands later became the home of Lord Mountbatten of Burma, known locally as "Lord Louis". He was buried in Romsey Abbey after being killed in an IRA bomb explosion in Ireland on 27 August 1979. In 1947, Mountbatten was given his earldom and the lesser title "Baron Romsey, of Romsey in the County of Southampton".
After Lord Mountbatten of Burma died, his titles passed to his elder daughter, Lady Brabourne, who thus became Lady Mountbatten of Burma. Her eldest son was styled by the courtesy title "Lord Romsey" until he inherited the title of Lord Brabourne in 2005.
The Prince and Princess of Wales spent the first night of their honeymoon at Broadlands.
During 2007 Romsey celebrated the 400th Anniversary of the granting of its Charter by King James I with a programme of events from March through September, including a visit on 8 June from the Queen and the Duke of Edinburgh. (Source - Wikepedia)