Southsea is a seaside resort and a geographic area of Portsmouth, Portsea Island in the ceremonial county of Hampshire, England.

[2] As the resort grew, it adopted the name of nearby Southsea Castle, a seafront fort constructed in 1544 to help defend the Solent and approaches to Portsmouth Harbour.

[11] Before the 16th century Southsea was principally composed of small farms, open grassland and undrained marshland (morass), outside the main naval base and the city itself.

However the growing expectation of a possible French attack on the naval base led Henry VIII to order the building of Southsea Castle in 1544, adjacent to the channel approaches to Portsmouth Harbour.

[12] Henry VIII visited Southsea Castle in 1545, from where he witnessed the sinking of the warship Mary Rose in the Solent.

[13] The first references to the development of the suburb appear in the Portsea Poor Rate returns of 1790 and describe small areas of building and farming plots.

Although the streets still exist, many of them were among the most heavily bombed areas of Portsmouth in the Second World War, and like much of Southsea they experienced significant redevelopment in Postwar Britain.

In 1851 St Jude's CofE church was built on Kent Road to a design by Thomas Ellis Owen.

[18] The remaining marshland, known locally as The Great Morass was drained, leading to the creation of Southsea Common, some 480 acres (about 2 km2) of open grassland.

Due to military requirements for clear lines of fire adjacent to Southsea Castle, the area was developed and remains today as a park and garden.

In 1857 Southsea gained its own Improvement Commissioners responsible for paving, street cleaning and public lighting.

[23] By the mid to late Victorian era, Southsea had become recognised as a largely middle-class neighbourhood, with many naval officers and other professionals taking up residence.

During this time the writer Sir Arthur Conan Doyle lived in Portsmouth, moving to Southsea in June 1882 with less than £10 (£1300 today[24]) to his name.

Southsea continued to thrive as a resort destination and a suburb of Portsmouth in the inter-war years, with many visitors in summer.

[28] Following the end of the war, in 1945 Southsea and the rest of Portsmouth embarked on a massive clearance and rebuilding scheme.

[31] On 9 August 2011 a fire broke out at the former Joanna's Nightclub, then derelict and later demolished, opposite South Parade Pier.

The Common owes its existence to the demands of the military in the early nineteenth century for a clear range of fire from the harbour defences at any enemy ships which dared to approach Portsmouth and its dockyard.

On 6 June 1994 a drumhead service was held on Southsea Common in front of the Portsmouth Naval Memorial to commemorate the 50th anniversary of D-Day.

The service was attended by all the heads of the states which had participated in the allied landings, notably HM Queen Elizabeth II and US President Bill Clinton.

On 28 June 2005 the Common was a venue for the Trafalgar 200 celebrations, the seafront an ideal point from which to witness the International Fleet Review and evening firework display.

[36][37] In July 2015 and 2016 Southsea Common hosted the America's Cup World Series sailing event.

[38] Canoe Lake[41] is the last remnant of an area of marsh and open water known as the Great Morass, drained in 1886, on which much of Southsea now sits.

Some marine wildlife can be spotted in the lake, including fish, crabs, moon jellyfish,[42] and reportedly even small sharks.

Summers tend to be warm with fewer extreme high temperatures than other areas in the South East of England.

Hovertravel operates a regular hovercraft service to Ryde on the Isle of Wight from Southsea seafront.

[53] The town is home to the UK's most successful club, winning 21 out of 53 national championships as of 2023, in addition to 16 out of 36 Nautilus Tournaments as of 2022.