Sea routes and anchorages II: Portsmouth, Spithead and St Helen's: ‘his Ma.ts Shipps returning out of the Sea in any distresse, with the losse of cables or Anchors or with her masts borne over:board, Portsmouth is a safe place to save men ships & goods, whereas comeing any further a Southerly storme may bee the destruction of all’

Portsmouth Harbour and St Helen’s and Spithead anchorages were vital to Britain’s navy for 2,000 years. From C3–5 AD, Portchester Castle, at the head of the harbour, operated as a Roman cross-Channel hub and provided national facilities for Classis Britannica. From c.1200, they were augmented by the Plantagenet galley dock on Portsea Island, and in 1495 superseded by the first permanent drydock. The Isle of Wight, invaded by the Danes in 998 and the French in 1340 and 1545, would became an essential naval defence: a militarised barrier and buffer. Henry VIII built St Helen’s bulwark on the island in 1539–45 to protect its anchorage and victualling facilities. In 1719, St Helen’s abandoned C13 church tower became the first seamark for Portsmouth’s eastern approach and the station to await a favourable wind.
By the end of the C16, when Britain was trading and waging war beyond the continental shelf, the navy could access the Atlantic faster from the south coast than from the Rivers Thames and Medway. Despite advantageous C16/17 reports regarding operations and expeditions, Portsmouth had to combat metropolitan preferences and prejudices. By the mid-C17, however, the navy acknowledged Portsmouth’s superb natural assets and rebuilt its drydock in 1658. Thenceforth, the navy prioritised Portsmouth in technological innovations. The harbour, sheltered strategically and climatically by the Isle of Wight, could accommodate the fleet. Spithead anchorage, unsurpassed for assembly and supply, was the scene of spectacular fleet reviews, even during the 1797 Spithead Mutiny. Focusing on the late-C16 to early-C19, this chapter will explain how Portsmouth, Spithead and Saint Helen’s endured as a fortified seascape to support war.