The Palmerston Forts

Victorian defences along Portsdown Hill

The Palmerston Forts are a chain of Victorian fortifications built along the crest of Portsdown Hill in the 1860s, forming a defensive line designed to protect Portsmouth and its naval dockyard from a landward attack. The forts were commissioned under the premiership of Lord Palmerston, following a Royal Commission report that warned of the vulnerability of the dockyard to a French invasion.

Five forts were built along the hill: Fort Wallington, Fort Nelson, Fort Southwick, Fort Widley and Fort Purbrook, running from west to east. Together they formed a continuous line of fire across the ridge, with each fort positioned to cover the gaps between its neighbours. The forts were built of brick and earth, with deep dry ditches, thick ramparts, underground magazines and casemated gun positions. They were armed with heavy artillery, including the latest rifled muzzle-loading guns of the period.

The forts were nicknamed Palmerston's follies because the French invasion they were designed to resist never materialised. By the time the forts were completed, the threat had receded and advances in military technology were already making fixed fortifications of this type obsolete. The forts were never tested in battle and their guns were never fired in anger.

Despite this, the forts had later military uses. Fort Southwick was adapted during the Second World War as the headquarters of the Allied Naval Commander Expeditionary Force. It was from the underground plotting rooms at Fort Southwick that Admiral Bertram Ramsay coordinated the naval operations for D-Day on 6 June 1944. This gives Fort Southwick a historical significance far beyond its original purpose.

Fort Nelson is now home to the Royal Armouries collection of artillery, from medieval cannon to modern field guns, and is open to the public free of charge. Fort Widley is managed by Portsmouth City Council and hosts various activities. Fort Southwick offers occasional guided tours of the D-Day tunnels.