The construction of HMS Portsmouth in the dockyard at Portsmouth marked the end of more than a century when the naval yard was engaged solely in repairing and refitting existing ships and offered the promise of a big improvement in the local economy.

Portsmouth was a fourth rate ship-of-the-line Phoenix Class frigate, originally designed and built to carry 38 guns, but in the 1670s her armament was increased to 46 guns. She was blown up in action in 1689, during an action against the French, during what is now known as the Nine Years War.

Frigates were the hardest worked warships of the age of sail, the term "frigate" originally referred to a method of construction, rather than to any perceived special role, but they were principally engaged in raiding activities, convoy patrols, reconnaissance missions and message and personnel carrying.

Occasionally, if there was a shortage of the larger ships-of-the-line (more correctly known at the time as battleships-of-the-line, or ships-of-the-battleline), then frigates would fill in gaps as an emergency measure.

They were much smaller than the battleships and carried far less armament, but they were very strongly built and, because they were required to carry less weight, they were considerably faster and far more maneuverable, and thus could run rings around a potentially far more powerful opponent.

A frigate would normally have to come to much closer quarters than any of its larger contemporaries, as apart from carrying less guns, their cannon were usually smaller, typically eight to 24-pounders, where as the "74s" (named for the number of heavy guns they carried) usually had several 32-pounders in their armoury.

It's worth noting that although the building of HMS Portsmouth signalled the end of more than a century during which no new ships were built at Portsmouth Dockyard, the town was never destined to rank among the busiest shipyards in the country, mainly because its geographic position made it the perfect base for quick turnaround on repairs, refits and reprovisioning.

This meant that the naval authorities preferred to make sure that there was always plenty of capacity at Portsmouth to fulfill these roles, limiting the facilities available for new construction work, most of which was shared among yards from devenport to Chatham and along the Thames Estuary.