There have been settlements in the area since before Roman times, mostly being offshoots of Portchester, which was a Roman base (Portus Adurni). Portsmouth is commonly regarded as having been founded in 1180 by the Anglo-Norman lord Jean de Gisors.
1181 Portsmouth's first real church was built when a chapel dedicated to Thomas Becket was erected by Augustinian monks. The modern Portsmouth Anglican Cathedral is built on the original location of the chapel.
1194 King Richard gave Portsmouth its first Royal Charter granting permission for the borough to hold a fifteen day annual "Free Market Fair", weekly markets, to set up a local court to deal with minor matters, and exemption from paying the annual tax, with the money instead used for local matters
1200 King John's desire to invade Normandy resulted in the establishment of Portsmouth as a permanent naval base, and soon afterward construction began on the first docks.
During the thirteenth century Portsmouth was commonly used by Henry III and Edward I as a base for attacks against France.
1418 Henry V built the first permanent fortifications of Portsmouth. The wooden Round Tower, one of Portsmouth's oldest permanent fortifications, to defend the entrance to Portsmouth Harbour.
Henry VII rebuilt the fortifications with stone and assisted Robert Brygandine and Sir Reginald Bray in the construction of the world's first dry dock.
1494 Henry VII built The Square Tower
1495 Henry VII founds Portsmouth Dockyard
1527 Henry VIII decreed that Portsmouth be home of the Royal Navy he founded and extends the Dockyard
1544 Henry VIII built the fort which became known as Southsea Castle. Although it would not have been called that at the time it is recorded as "Southsea Castle" in a map of 1724.
1545, The Mary Rose founders off Southsea Castle, with a loss of about 500 lives, while going into action against the French fleet.
1563 Portsmouth has a population of maybe 2,000 but 300 are killed by an outbreak of plague
1663 A new wharf, the Gun Wharf is built for the navy and Dockyard
1787 11 ships sailed from Portsmouth, to establish the first European colony in Australia. It is known today as the First Fleet in Australia.
1802 Marc Isambard Brunel, the father of famed Portsmouth engineer Isambard Kingdom Brunel, established the world's first mass production line at the Portsmouth Block Mills, to mass
produce pulleyblocks for rigging on the Royal Navy's ships At its height the Dockyard was the largest industrial site in the world.
1806 Engineering Genius, Isambard Kingdom Brunel is born in Portsmouth
1809 a new suburb began to grow. It became known as Southsea after the castle. The first houses were built for skilled workers in the 'mineral' streets (Silver Street, Nickel Street etc.)
1812 Charles Dickens is born in Portsmouth
1835-1860 Southsea begins to grow. A prominent architect during this period was Thomas Ellis Owen who built properties in Kent Road, Queen’s Terrace, Sussex Terrace, Beach Road, Grove Road South, Clarendon Road, Osborne Road and Portland Terrace.
1840 Horse drawn buses start to run in Portsmouth
1847 The railway reaches Portsmouth
1860 HMS Warrior launched
1901-1903 Trams are converted to electricity
1916 first aerial bombardment when a Zeppelin airship bombed it during the First World War.
1922 The corporation purchases Southsea Common
1926 Portsmouth granted city status, following a long campaign by the borough council. The application was made on the grounds that Portsmouth was the "first naval port of the kingdom".
1936 The last tram runs in Portsmouth
During the Second World War, the city was bombed extensively destroying many houses and the Guildhall. Its status as a major port was the key factor in the Luftwaffe's decision to bomb it so heavily.
1944 Southsea beach and Portsmouth Harbour were vital military embarkation points for the D-Day landings. Southwick House, just to the north of Portsmouth, had been chosen as the headquarters for the Supreme Allied Commander, US General Dwight D. Eisenhower, during D-Day
In the 1960s and early 1970s large areas of the city are rebuilt as much of the city's housing stock was damaged and more was cleared in an attempt to improve the quality of housing. Post-war redevelopment throughout the country was characterised by utilitarian and brutalist architecture, with Portsmouth's Tricorn Centre one of the most famous examples. More recently, a new wave of redevelopment has seen Tricorn's demolition, the renewal of derelict industrial sites, and construction of the Spinnaker Tower.
1982 The Mary Rose is raised
1987 HMS Warrior comes to Portsmouth
2001 A new shopping centre opens at Gunwharf
2005 The Spinnaker Tower opens
2015/6 Americas Cup Race hosted in Portsmouth
2017 The Queen Elizabeth warship arrives in Portsmouth