The area surrounding Pembroke provides ample evidence of human habitation stretching back as far as the end of the last Ice Age (NPRN 92727), with standing stones, prehistoric tombs (NPRN 276031) and Roman coin hoards. The town of Pembroke can be dated to the arrival of the Normans in 1093, when Roger Montgomery ordered the construction of a wooden fortress on the site of the current castle (NPRN 94945). The position was ideal for defence, being on a ridge surrounded on three sides by the River Cleddau, and with access down to the river below. The town developed around the castle, which was steadily replaced with stone, and by 1135 the town had been granted its first charter. In the late thirteenth or early fourteenth century a stone curtain (NPRN 32127) was built around the town.
In 1400 Pembroke was spared from attack by Owain Glyndwr, when the town constable paid the Welsh leader a considerable sum to bypass it. However, during the English Civil War Pembroke is noted for having been attacked by both sides, following the mayor switching allegiances. The town subsequently suffered a period of decline, which lasted in 1814 when the Royal Navy Dockyard moved from Milford Haven to the adjacent Pembroke Dock (NPRN 34318). In 1952 the area became part of the new Pembrokeshire Coast National Park, and in 1977 it was designated an Outstanding Conservation Area.

K Steele, RCAHMW, 9 January 2009