Most probably there was an Iron Age hill fort on the site of the castle (many of these actually date from the Bronze Age) given it's wonderful defensive position and its domination of the lowest fording point of the Western Cleddau. Castles in Wales often occupy Iron Age sites as they were such good defensive positions in the landscape with existing fortifications in the shape of banks and ditches that could be quickly renovated and included into the early castle. The building of the castle has obscured all traces of Iron Age remains unfortunately.

The well known theory that it could have been a Danish settlement prior to the Norman conquest of West Wales in 1093/94 (from the suggested name Hafna's Fjord) is not correct as the name Haverford originates from Haefer ('he-goat or buck') Ford. The name developed to Haverfordwest to distinguish it from Hereford.

Haverfordwest Castle was established around 1110 and the town would have most probably been established at the same time.

The castle was originally built by Tancred the Fleming so the original medieval town and castle would have been Flemish not Norman. A little piece of Flanders in West Wales. It protected the main area of Flemish settlement in Pembrokeshire, the Cantref of Rhos, to the west. The castle remained in Tancred's family until 1210.

The Flemish were settled in this area from 1108 to protect the main Norman stronghold at Pembroke from Welsh attacks from the north.

Like many castles in Wales Haverfordwest has access to the sea which was vital for communications in an often hostile land. Hence it developed as a port.

The original castle would have been a hastily assembled wooden castle of motte and bailey or possibly ringwork design.

The town originally developed following the building of the castle on the northern and western slopes adjacent to the castle gate in the area now occupied by Queens Square, Hayguard Lane and St Martin's Church. There would have been town walls, originally in timber, but probably rebuilt in stone during the 1200s. The walls were derelict by the time of the Civil Wars in the 1640s and have since largely disappeared.

The castle was probably attacked during the fighting with Gruffydd ap Rhys Prince of Deheubarth in 1135 - 1136 but appears to have resisted any Welsh attempts to storm it.

1173 Haverfordwest has its first royal visit with Henry II returning from Ireland.

1188 Giraldus Cambrensis visited during his progress around Wales preaching for the 3rd Crusade that Richard I (Lion Heart) led to the Holy Land.

By 1200 the castle had its first stone buildings with the rectangular north eastern tower that functioned as the Keep being rebuilt in stone.

Prior to 1210 an Augustine Priory was founded in the town.

1210 King John takes the castle into royal control removing Robert fitz Richard from control.

1210 King John make several visits to Haverfordwest on journeys to and from Ireland.

1213 King John grants the castle to the very powerful and incredibly wealthy William Marshal Earl of Pembroke in return for a huge sum of money.

It is probable that William Marshal extensively rebuilt the castle in stone at this time (he was already doing the same at Pembroke). Timber walls, towers and gatehouses would be replaced with stone.

1217 Haverfordwest threatened but not attached by Llywelyn ap Iorwerth (Llywelyn the Great) Prince of Gwynedd

1220 Llywelyn attacks and burns the town but fails to storm the castle

13th century sees substantial growth of the town as a commercial centre due to its position at the centre of Pembrokeshire and its links to the sea.

Sometime prior to 1246 the Dominican Friary was established.

1248 Humphrey de Bohun II (of the powerful marcher family of de Bohun) acquired the castle.

1257 Haverfordwest resists attack by Llywelyn ap Gruffydd Prince of Gwynedd and later Prince of Wales (Llywelyn the Last).

1265 Haverfordwest castle taken by William de Valance, Earl of Pembroke, during the Barons War.

1274 The castle was granted to Humphrey de Bohun III by the Crown.

1284 Edward I and Queen Eleanor visit during a royal pilgrimage to St Davids.

1289 Queen Eleanor acquires the castle from Humphrey de Bohun III. She borrowed the huge sum of £407 for improvements. This was the final major medieval building phase with the construction of extensive stone buildings to the south and east of the inner ward. Most of the ruins of the castle seen today date from this period. The project may never have been finished as Eleanor died in 1290.

The castle remained in Royal hands but was granted out to various tenants.

David Llewellyn - Pembrokeshire Record Office, part of Pembrokeshire County Council

History of Haverfordwest - Part Two