England’s King John I had in 1200 reaffirmed the rights and privileges awarded by Richard II to the city of Portsmouth, which had rapidly eclipsed the older settlement of Portchester, with its Roman and medieval castle, as the sea receded from that site.
King John's desire to invade Normandy resulted in the establishment of Portsmouth as a permanent naval base.
Shortly afterwards, construction had begun on the first docks, and the Hospital of St Nicholas, which performed its duties as an almshouse and hospice.
During the thirteenth century Portsmouth, was commonly used by Henry III and Edward I as a base for attacks against France.
By the fourteenth century, commercial interests had grown considerably.
Common imports include wool, grain, wheat, woad, wax and iron; however the port's largest trade is in wine from Bayonne and Bordeaux.
A French fleet led by Nicholas Béhuchet had raided Portsmouth in 1338, destroying much of the town, with only the local church and hospital surviving.
Edward III had given the town exemption from national taxes to aid reconstruction.
Only ten years later, the town had been struck by the Black Death.
To prevent the regrowth of Portsmouth as a threat, the French had again sacked the town in 1369, 1377 and 1380.
Henry V, who built the first permanent fortifications of Portsmouth, had in 1418 ordered a wooden Round Tower be built at the mouth of the harbor, which was completed in 1426.
Henry VII has rebuilt the fortifications with stone, raised a square tower, and assisted Robert Brygandine and Sir Reginald Bray in the construction of the world's first dry dock.
Although King Alfred may have used Portsmouth to build ships as early as the ninth century, the first warship recorded as constructed in the town is the Sweepstake, built in 1497 in the dry dock.