The industrial town of Portsmouth, situated on the "island" of Portsea, owes its importance to its magnificent natural harbor. For centuries, from the time of the Armada onwards, it was the principal base of the Royal Navy, while in more recent times Portsmouth has also become the most important naval port
in Great Britain; thus in 1981 the town was the port of departure and the marine command headquarters for the British troops in the war against Argentina over the Falkland Islands. Thus many of the popular tourist attractions in Portsmouth are related to the naval history.
Three famous historic ships provide evidence of past naval might: Lord Nelson's "H.M.S. Victory", the "Mary Rose" of Henry VIII, and the "H.M.S. Warrior", the Royal Navy's first warship.
In the last few years an attempt has begun to be made to address the problem of the town's need to expand - a problem arising from the fact that it is bounded by the sea to the west, south and east, and by Ports Down to the north. Banks of earth and dikes have been built up in order to create new areas of land. In the Hampshire Basin towards Winchester the fertile soils with their Tertiary deposits provide excellent conditions for intensive agriculture.
The strategic importance of this site on the Channel was recognized by the Romans, who built a fort at Portchester, on a promontory just west of Portsmouth - the only Roman fort in Britain or northern Europe which was never destroyed, although frequently captured. The Normans took over the Roman fortress and it was strengthened by Henry II. Richard II had the site extended and built a fortified palace adjoining the keep. In 1415 Henry V assembled his troops here before setting sail for France. In the Second World War Portsmouth's strategic importance as a naval base led to large parts of the town being destroyed.