Claim: Charles Dickens was European.

Portsmouth -LRB- -LSB- ˈpɔrtsməθ -RSB- -RRB- is a port city in Hampshire , England , mainly on Portsea Island , 70 mi south-west of London and 19 mi south-east of Southampton . It is the United Kingdom 's only island city and has a population of 205,400 . The city forms part of the South Hampshire built-up area , which also covers Southampton and the towns of Havant , Waterlooville , Eastleigh , Fareham , and Gosport .   The city 's history can be traced to Roman times . A significant naval port for centuries , Portsmouth has the world 's oldest dry dock and was England 's first line of defence during the French invasion in 1545 . Special Palmerston Forts were built in 1859 in anticipation of another invasion from continental Europe . By the early-19th century , Portsmouth was the most heavily fortified city in the world , and was considered `` the world 's greatest naval port '' at the height of the British Empire throughout Pax Britannica . The world 's first mass production line was set up in the city , making it the most industrialised site in the world . During the Second World War , the city was a pivotal embarkation point for the D-Day landings and was bombed extensively in the Portsmouth Blitz , which resulted in the deaths of 930 people . In 1982 , a large proportion of the task force dispatched to liberate the Falkland Islands deployed from the city 's naval base . Her Majesty 's Yacht Britannia left the city to oversee the transfer of Hong Kong in 1997 , which marked for many the end of the empire .   Portsmouth is one of the world 's best known ports . HMNB Portsmouth is considered to be the home of the Royal Navy and is home to two-thirds of the UK 's surface fleet . The city is home to some famous ships , including HMS Warrior , the Tudor carrack Mary Rose and Horatio Nelson 's flagship , HMS Victory -LRB- the world 's oldest naval ship still in commission -RRB- . The former HMS Vernon naval shore establishment has been redeveloped as a retail park known as Gunwharf Quays . Portsmouth is among the few British cities with two cathedrals : the Anglican Cathedral of St Thomas and the Roman Catholic Cathedral of St John the Evangelist . The waterfront and Portsmouth Harbour are dominated by the Spinnaker Tower , one of the United Kingdom 's tallest structures at 560 feet . Nearby Southsea is a seaside resort with a pier amusement park and medieval castle .   Portsmouth F.C. , the city 's professional football club , play their home games at Fratton Park . The city has several mainline railway stations that connect to London Waterloo amongst other lines in southern England . Portsmouth International Port is a commercial cruise ship and ferry port for international destinations . The port is the second busiest in the United Kingdom after Dover , handling around three million passengers a year . The city formerly had its own airport , Portsmouth Airport , until its closure in 1973 . The University of Portsmouth enrols 23,000 students and is ranked among the world 's best modern universities . Portsmouth is also the birthplace of author Charles Dickens and engineer Isambard Kingdom Brunel .