Portland Naval Base
Portland Roads, sheltered from westerly storms by Chesil Beach and the heights of the Island, had been much used as an anchorage at least since Henry VIII built his forts to protect it. It could however be a death-trap if the wind were from a different quarter, and by the time of Napoleon it was practically undefended. To provide a harbour where ships could lie safely in any weather, a breakwater was needed; and after the one protecting Plymouth Sound had been completed it was decided to use the experience gained and build one at Portland. A British naval port here would lie directly opposite the one the French (then our most likely enemies) were developing at Cherbourg, and ships based on it would be well-placed to strike against any French assault on Portsmouth, Plymouth, or the Channel Islands. Accordingly convict labour was drafted into the Island, and work started. By 1860 the French threat appeared serious, and rings of forts were commenced round Portsmouth and Plymouth. At the same time the Verne Citadel was begun, with the Nothe Fort at Weymouth, and the following years saw first the completion of the Old Breakwater and then, about 1880, that of the defences. Much of the stone used in the Breakwater was actually quarried from the huge ditch surrounding the Citadel.
When the fortifications were complete, heavy guns in the Verne and the adjoining battery could cross with those of Upton Fort to command the whole of Weymouth Bay with a plunging long-range fire. The batteries at East Weares and the Nothe, nearer sea-level, could sweep the harbour approaches with more horizontal fire, while the small forts on the Breakwater itself gave close protection.
The appearance of the fast torpedo-boat, however, made further precautions necessary. Such vessels might use their small size, manoeuvrability, and speed to avoid the protecting gunfire and sink battleships at anchor with torpedoes. To meet this threat the New Breakwater was built to enclose the whole harbour, leaving only narrow entrances which could easily be blocked with boom defences against intruders.
Up to 1914 Portland remained one of the chief bases of the Channel Fleet: but British naval arrangements based on the nineteenth century idea that France would be the enemy had to be drastically changed when Germany became the danger. The chief operations area for heavy ships in 56 home waters changed from the Channel to the North Sea, and the old Channel Fleet was disbanded. Portland therefore lost much of its former value, though it returned to temporary importance during the Second World War when the French coast was in the hands of Germany.