Last updated: 24 November 2010
Pembroke Castle most likely sits on early fortifications (Roman habitation is known in the area), which is no suprise given its strategic location.
Either side of the ridge on which it sits run two tidal inlets, and it can control sea traffic in and out of the natural harbour. For the Norman conquerors in the 11th and 12th centuries, this would prove to be an important strategic consideration.
The castle as a Norman fort was established in 1093, 27 years after the Battle of Hastings, by Roger of Montgomery, one of William I's most trusted allies. Of course, originally it was erected swiftly using earth and timber, but it was unusual in remaining in this form - and unbreached - for almost 100 years.
It was in 1189 that a famed knight, William Marshall, was married to Isabel de Clare, daughter of Richard de Clare ('Strongbow'), second Earl of Pembroke. Marshall became the third earl, and set about fortifying the castle.
Marshall created a huge stone castle in a classic Norman concentric design. One of the best-known features of the castle is the colossal circular keep with domed roof - still scalable these days via the spiral staircase.
After the death of Marshall, five of his sons were Earls of Pembroke, each of them dying childless. The Earldom passed to William Marshall's granddaughter Joan de Munchensy's husband, William de Valance.
The castle and its earldom passed between various families and the crown through the 14th century, surviving the ravages of the Owain Glyndŵr revolt. In 1457, under Jasper Tudor, earl of Pembroke, his nephew the future King Henry VII was born within the walls.
Pembroke Castle saw military action once more in the Civil War when Oliver Cromwell personally oversaw its siege and partial destruction.