On Monday 19 August 1940 a single Junkers Ju 88 came up the haven low and fast. It dropped its bombs on the Llanreath oil tank depot on the south shore and turned for home. One bomb hit a tank of fuel oil. Within minutes the tank was burning; within hours, four more had caught. The fire would burn for eighteen days, sending a column of black smoke visible across the Bristol Channel - the largest conflagration in the United Kingdom since the Great Fire of London in 1666. Fire brigades from twenty-two stations were summoned. Among the crews that came was a team from the National Fire Service in Cardiff. Five of them never went home. On 21 August 1940, when one of the burning tanks ruptured catastrophically, Frederick George Davies, Ivor John Kilby, Clifford Mills, Trevor Charles Morgan, and John Frederick Thomas were killed - five men in their twenties and thirties, sent to a fire so large no peacetime training had prepared them for it. A memorial at Llanreath now records their names. They are buried, in part, in Pembroke Dock Military Cemetery, believed to be the only dedicated military cemetery in Wales.

The dockyard was the reason for the town and the measure of it. The Admiralty surveyed the haven in 1757, lobbied Parliament for years, and finally laid the keel of HMS Valorous and HMS Ariadne in 1814 - both launched on the same February day in 1816. Over 112 years the yard would launch 263 Royal Navy vessels and five royal yachts, the last being the tanker Oleander on 26 April 1922. Workers lived in the new town that grew alongside; officers occupied the Terrace, a row of Georgian houses inside the dockyard walls. Two Martello towers of dressed Portland stone guarded the corners, garrisoned by artillery sergeants and their families. In 1845 the Royal Marines arrived to defend the place; by the 1850s, defensible barracks rose on Llanion Hill, and by 1904 four brick barrack blocks housed a thousand troops. Then in 1925 the Admiralty, scrambling for postwar savings, declared Pembroke Dock and Rosyth redundant. The town petitioned Prime Minister Stanley Baldwin to spare them. The reply was uncompromising: the dockyards were unnecessary. The yard closed in 1926, exactly the year the General Strike paralyzed Britain. The town would spend the next five years in deepening unemployment.

Rescue came in 1931 in the form of flying boats. No. 210 Squadron RAF arrived with Supermarine Southampton aircraft, lifting off from a specially-built spillway on the haven. For almost thirty years the Royal Air Force would call Pembroke Dock home. The base produced one notable wing commander in the 1930s: Sir Arthur Harris - later known to the world as Bomber Harris - flew Southamptons here. By 1938 the Short Sunderland, the great four-engined patrol flying boat the crews called 'the Mighty Sundies,' began replacing older aircraft. When Holland fell in June 1940, several Dutch naval flying boats made for Pembroke Dock and became 320 (Netherlands) Squadron RAF. By 1943 the base was home to ninety-nine aircraft - the largest flying boat station on the planet. Crews from Britain, Australia, Canada, the Netherlands, and the United States Navy flew from these waters, hunting U-boats and rescuing downed airmen across the western approaches and the Bay of Biscay. The Sunderlands kept flying from here until 28 February 1957, when the last squadrons disbanded. Final closure came in 1959.

The dockyard wall is still substantially complete. Two of the ten original building slips remain, and the dry dock survives. The Garrison Chapel at the end of the Terrace was rebuilt with European Union Objective One funding and now houses the Pembroke Dock Heritage Centre, where a replica Sunderland cockpit lets visitors fly a simulated patrol over the haven. The two listed RAF hangars still stand - and one of them holds a strange piece of cinema history. In 1979, Marcon Fabrications used the eastern hangar to build the full-scale Millennium Falcon prop for The Empire Strikes Back, a project nicknamed the Magic Roundabout. Star Wars fans walking the perimeter still pause to imagine it. In 2021 the council approved a 60 million pound marine energy project that will demolish and infill significant parts of the historic dockyard, including the Grade II* graving dock and the timber pond, despite protests from SAVE Britain's Heritage and the Georgian Group. The Commodore Trust argued the plans would destroy 'a rare, if not unique, group of listed monuments.' The dockyard's third life - as a marine energy hub - will sit on the ashes of its first two.

Pembroke Dock has been talked about, periodically, as needing a new name. A 1960s referendum rejected the change. The proposal came back in 2003: Pembroke Haven? Pembroke Harbour? A return to Paterchurch? The arguments were about image, about a reputation for unemployment and industrial decline. Each time the town stayed Pembroke Dock. There is a stubbornness to the name that matches the place - it refuses to forget what made it. The bombing of May 1941 killed thirty more people in a single night and damaged nearly two thousand houses. The military cemetery holds Commonwealth airmen and sailors, some unidentified. The town's notable alumni include the rugby international Ernie Finch, naval architect John Harper Narbeth, and the writer Phil Carradice. In 2022 one councillor, Billy Gannon, resigned amid persistent rumours that he was Banksy - rumours he never quite confirmed or denied. Pembroke Dock has always been more than its name suggests.