Tenby, United Kingdom

After the 1260 attack, the Earl of Pembroke at the time, William de Valence, ordered the completion of the Tenby town walls. The stone curtain wall, towers, and gates enclosed a large part of the settlement—now known as the "old town". In the Late Middle Ages, Tenby was awarded royal grants to finance the maintenance and improvement of its defences and the enclosure of its harbour. With the construction of the town walls, Tenby Castle was made obsolete and had been abandoned by the end of the 14th century. William de Valence granted Tenby a charter in 1290.

In 1452, King Henry VI gave the Marcher Lordship (and associated Earldom) to Jasper Tudor, his half-brother and uncle to the future Henry Tudor. In 1457, Tudor agreed to divide the costs of refurbishing and improving Tenby's defences with the town's merchants because of its economic importance to this part of Wales. Improvements included widening the dry ditch along the outside of the town walls to 30 feet (9.1 m), raising the wall's height to include a second tier of higher arrow slits behind a new parapet walk and adding additional turret towers to the ends of the walls where they abutted the cliff edges.

Traders sailed along the coast to Bristol and Ireland and further afield to France, Spain, and Portugal. Exports included wool, skins, canvas, coal, iron, and oil. It was during this period that the town was so busy and important; it was considered to be a national port. During the Wars of the Roses, Henry Tudor, the future King Henry VII of England, sheltered at Tenby before sailing into exile in 1471.

In the mid-16th century, the large D-shaped tower formerly known as the "Five Arches tavern" was built following fears of a second Spanish Armada. Tenby was formally incorporated as a borough by Elizabeth I in 1581.

Two key events caused the town to undergo a rapid and permanent decline in importance. First, Tenby declared for Parliament in the English Civil War. It resisted two attempts by the Royalists forces of Charles Gerard, who took most of the rest of South Wales. However, in the Second English Civil War the commander of Tenby Castle declared for the King in 1648, although ten weeks later the shattered town was surrendered to the parliamentarian Colonel Thomas Horton, who welcomed Oliver Cromwell shortly afterwards. Second, a plague outbreak killed half of the town's remaining population in 1650.

With limited infrastructure, resources, and people, the town's economy fell into decline. Most of the merchant and business class left, resulting in the town's decay and ruin. By the end of the 18th century, John Wesley noted during his visit how: "Two-thirds of the old town is in ruins or has entirely vanished. Pigs roam among the abandoned houses, and Tenby presents a dismal spectacle."

Another war led to a resurgence in Tenby's fortunes. Since 1798, the French General Napoleon Bonaparte had begun conquering Europe, restricting the rich British upper classes from making their Grand Tours to continental spa towns. In 1802, local resident, merchant banker and politician, Sir William Paxton, bought his first property in the old town. From this point onwards, he invested heavily in the area with the full approval of the town council.

With the growth in saltwater sea-bathing for health purposes, Paxton engaged engineer James Grier and architect Samuel Pepys Cockerell (the same team who had built his home at Middleton Hall) to create a "fashionable bathing establishment suitable for the highest society." His sea-bathing baths came into operation in July 1806 and, after acquiring the Globe Inn, transformed it into "a most lofty, elegant and convenient style" to lodge the more elegant visitors to his baths. Cottages were erected adjoining the baths with adjoining livery stables and a coach house.

A road was built on arches overlooking the harbour at Paxton's full expense in 1814. He had a private act of Parliament passed that enabled fresh water to be piped through the town. Despite these accomplishments, his 1809 theatre was closed in 1818 due to lack of patronage. The Market Hall was completed in 1829 and remodelled to serve as Tenby Town Hall in 1860.

Paxton also took in "tour" developments in the area as required by rich Victorian tourists. This included the discovery of a chalybeate spring in his own park at Middleton Hall, and coaching inns from Swansea to Narberth. He built Paxton's Tower, in memorial to Lord Nelson, whom he had met in 1802 when mayor of Carmarthen. Paxton's efforts to revive the town succeeded, and after the Battle of Trafalgar, the growth of Victorian Tenby was inevitable.

The borough was reformed to become a municipal borough in 1836.