Apart from its proximity to the French coast, Dover has never had much to recommend it as a site for a major harbour. The shallow bay west of the River Dour's narrow estuary did offer some shelter against westerly gales, and shipping had been using it since the Bronze Age. But bay and estuary alike were constantly under threat from great banks of shingle moving inexorably eastward along the coast.
Romans and Saxons, early British kings and local residents all tried to keep the harbour functioning - largely in vain. The shingle always won in the end. When the sixteenth century dawned Dover harbour was derelict.
So were most of the ports and harbours in the area. Sandwich, Romney and Winchelsea had already been lost to silt, Hythe would be gone within 50 years. From Portsmouth to the Thames Estuary there was no safe harbour for crucial cross-Channel trade - or for the fledgling Royal Navy.
Enter Henry VIII in 1530. His interest aroused by a deputation headed by a local cleric, the King originally made a grant of £300 for the work, and was soon taking an active interest in the project. The work he funded was mainly the dredging of a semi-natural basin beneath the western cliffs - known somewhat ironically as Paradise - and the partial construction of a 240m south-eastern pier intended to block the advance of shingle.
The project failed, despite minor additions and alterations, for reasons later generations of civil engineers were to confirm: A much longer pier was needed, right out to deep water. Henry actually spent the enormous sum of £60,000 (confiscated from the Church) on the scheme, but by the time the money ran out, not even the foundations had been completed.
These foundations, later to be known as the Mole Rocks, dogged plans for the harbour for centuries to come. But without the longer wall the shingle and silt continued to build up, and by 1556 Paradise was virtually useless.
However, the south-eastern pier did have one important effect that was to determine the future shape of the harbour, and of Dover itself. Shingle deflected by the pier formed a long bank parallel to the shore, from the mouth of the Dour to the entrance to Paradise. This shingle bank was the key to the first real harbour at Dover.
The man who first realised the potential of the bank was a local, John True. He proposed using it as the foundation for a long wall, behind which would be a 'pent', in which the water from the Dour could be confined by a cross wall fitted with sluices. At low tide the pent-up water could be released to sweep away any shingle deposits which might have built up at the harbour mouth. This principle was first mooted some years earlier by the then Comptroller of the Navy, William Burrough, whose report to Queen Elizabeth I in 1576 on the desirability of developing Dover was probably the most crucial in the port's long history.
Eventually, after years of procrastination, the Queen agreed to a tax on all shipping entering or leaving the country, the proceeds to be spent on the improvements to Dover. True was appointed to plan and oversee the project.
His failure to carry the project forward meant True was soon replaced by Thomas Digges, a local mathematician and natural philosopher, who had originally proposed a vastly enlarged harbour on the site. After True's failure as a project manager, Digges was given the task of developing a less ambitious design.
The key feature was still the 'long wall' founded on the off-shore shingle bank and forming the Pent. Over three months in 1583, 1,000 men using 500 carts built a wall 800m long and several metres high. At the same time a cross wall containing flood gates and sluices was built out from the land to close off the Pent.
Digges' improvement on True's plans was to channel water from the Pent to flush out the original Paradise. Renamed Little Paradise, this basin was also fitted with sluice gates to clear any shingle from its entrance. Between Little Paradise and the Pent the new currents soon created a tidal harbour eventually protected by new piers each side of its entrance.
By the end of the 16th Century Dover had a harbour which could cope with the demands of commercial traffic and Royal Navy alike. Little was to change for the next three centuries.