Rhuddlan Castle was begun by Edward I in 1277, immediately after he defeated Llywelyn ap Gruffydd.  In fact, Llywelyn made his submission to Edward in the bailey of the old castle, after which Edward immediately had it torn down.

“Rhuddlan first appears in recorded history in the last years of the eighth century, when there was no town of Rhyl and the shore road from Prestatyn to Abergele did not exist. Instead, the Clwyd and the marshes off its estuary, now reclaimed and drained and cultivated, formed a natural barrier athwart the coastal approach to the mountainous heart of North Wales. The settlement of Rhuddlan is likely to have owed its origin to the presence at this point, from very early times, of the lowest fording-place on the river, from which a track led across the marsh to Vaynol and beyond. Its position thus marked it out as a key point in the racial struggles which for some 600 years (c.700-c.1300) swayed to and fro across the Welsh and English border.

… in 1063, it is a royal seat of Gruffydd ap Llywelyn and the base from which that powerful prince (actually considered the last true High King of Wales) plundered the English lands as far east as Oswestry and Wrexham. In that year Gruffydd was driven from Rhuddlan by Earl Harold (Godwinson) and his palace burned.

… At the command, William the Conqueror, a new castle of the motte-and-bailey pattern, which marked every stage of the Norman penetration, was thrown up at Rhuddlan in 1073 by Robert of Rhuddlan, a kinsman and lieutenant of Hugh d’Avaranches, earl of Chester. Earlier, in the 1050s, Robert had been a squire at the court of King Edward the Confessor, by whom he had been knighted. From the Domesday book (1086) we learn that in return for an annual rent of L40, the Conqueror had granted him power over the whole of north Wales beyond the Clwyd; it was in this capacity that Robert made Rhuddlan the base from which he set out to exploit and consolidate the holding entrusted to him by the king in Gwynedd, and from which he also took his surname.”  http://www.castlewales.com/rhudln.html

“‘Rhudd’ is the old Welsh word for ‘red’ and ‘glan’ means ‘bank’. The Normans left us with ‘roe’, a word derived from the French ‘le rous’, meaning redhead. ‘Roeland’ is first mentioned in 1086 but by 1277 it was known as Rhuddlan and Edward I’s chosen location for a mighty scary castle.

For centuries, Rhuddlan had been a fiercely contested strategic location leading to much bloodshed. Edward’s muscle power triumphed long enough to build a muscle-bound symmetrical castle, showcasing the latest in ‘walls-within-walls’ technology. Edward I needed access to the sea to keep his castle supplied so he diverted the River Clwyd for over 2 miles (3.5km) to provide a deep-water channel for ships. The remains of a defended river gate still exist in the outer ring of the walls.

The castle also played a seminal role in Welsh history: it was here that a new system of English government was established over much of Wales by the Statute of Rhuddlan (1284) – a settlement that lasted until the Act of Union in 1536. After the Civil War the castle was rendered untenable – hence its present condition.”   http://cadw.wales.gov.uk/daysout/rhuddlancastle/?lang=en