Question: The medieval fortification Castle Hill was builty by this noble man who was also known as King of which country (after the 1250s)?

Context paragraphs:
Castle Hill, Mere: Castle Hill, also called Mere Castle, was a medieval fortification built by Richard, the Earl of Cornwall, in 1253 on a hill overlooking the village of Mere, Wiltshire, England.  The castle was constructed in stone, with six towers, inner buildings and gates.  It was abandoned in the 14th century and stripped of its stone and metalwork.  Only earthworks remain in the 21st century.

Akova Castle: The Akova Castle (Greek: Κάστρο της Άκοβας ) is a medieval fortification in Gortynia, Arcadia, Greece.  The medieval castle, also known as Mattegriffon, is built on top of a steep hill, inaccessible from the three sides.

Methoni Castle: The Castle of Methoni is a medieval fortification in the port town of Methoni, Messenia, in southwestern Greece.  The castle of Methoni occupies the whole area of the cape and the southwestern coast to the small islet that has also been fortified with an octagonal tower and is protected by the sea on its three sides.  Its north part, the one that looks to land, is covered by a heavily fortified acropolis.  A deep moat separates the castle from the land and communication was achieved by a wooden bridge.  The Venetians built on the ancient battlements and added on and repaired it during both periods that they occupied the castle.

Altes Schloss (Drügendorf): The small ringwork of the Altes Schloss ("old castle") is all that remains of a, now levelled, early medieval fortification on one of the projecting hill spurs of the Mirsberg Heights ("Mirsberger Höhe") on the Lange Meile in the valley of the Eggerbach.  The spur is called the "Schlossberg" ("castle hill").  The old castle site lies at a height of  sea level (NN) around 935 metres south-southeast of the Roman Catholic parish church of St. Margareta of Drügendorf in the Upper Franconian municipality of Eggolsheim in Bavaria, Germany.  No historical or archaeological information about this hillfort exists, and there have been no finds that might be able to be used to date the site.  Based on the design of the fortification it has been tentatively dated to the Carolingian-Ottonian period.  All that has survived is a ringwork with an outer ditch in places.  The fortification is protected today as heritage site number D-4-6132-0125: "Early Medieval Ringwork" ("Frühmittelalterliche Ringwallanlage").

Richard, 1st Earl of Cornwall: Richard (5 January 1209 – 2 April 1272), second son of John, King of England, was the nominal Count of Poitou (1225-1243), Earl of Cornwall (from 1225) and King of Germany (from 1257).  He was one of the wealthiest men in Europe and joined the Barons' Crusade, where he achieved success as a negotiator for the release of prisoners and assisted with the building of the citadel in Ascalon.

Sutton Valence Castle: Sutton Valence Castle is a ruined medieval fortification in the village of Sutton Valence in Kent, England.  It was built in the second half of the 12th century, probably by Baldwin of Bethune, the Count of Aumale.  Overlooking a strategic route to the coast, the original castle probably comprised an inner and an outer bailey and a protective barbican, with a three-storey high keep on its southern side.  It was passed into the Marshal and de Montfort families, before being given by King Henry III to his half-brother William de Valence in 1265, from whom the castle takes its current name.  It was abandoned in the early 14th century and fell into ruin.  In the 21st century the castle is managed by English Heritage, and the remains of the keep are open to the public.

Etal Castle: Etal Castle is a ruined medieval fortification in the village of Etal, Northumberland, England.  It was built around 1341 by Robert Manners, and comprised a residential tower, a gatehouse and a corner tower, protected by a curtain wall.  The castle was involved both in local feuding and the border wars between England and Scotland.  There was a battle between the rival Manners and Heron families outside the walls in 1428, and in 1513 it was briefly captured by King James IV of Scotland during his invasion of England.

Spur castle: A spur castle is a type of medieval fortification that uses its location as a defensive feature.  The name refers to the location on a spur projecting from a hill.  Ideally, a spur castle would be defended on three sides by steep hillsides, with the only vulnerable side the one where the spur joins the next hill.

Moorish Castle: The Moorish Castle is the name given to a medieval fortification in Gibraltar comprising various buildings, gates, and fortified walls, with the dominant features being the Tower of Homage and the Gate House.  Part of the castle itself also housed the prison of Gibraltar until it was relocated in 2010.  The Tower of Homage is clearly visible to all visitors to Gibraltar; not only because of its striking construction, but also because of its dominant and strategic position.  Although sometimes compared to the nearby "alcazars" in Spain, the Moorish Castle in Gibraltar was constructed by the Marinid dynasty, making it unique in the Iberian Peninsula.

Tintagel Castle: Tintagel Castle (Cornish: Dintagel , meaning "fort of the constriction") is a medieval fortification located on the peninsula of Tintagel Island adjacent to the village of Tintagel, North Cornwall in the United Kingdom.  The site was possibly occupied in the Romano-British period, as an array of artefacts dating to this period have been found on the peninsula, but as yet no Roman era structure has been proven to have existed there.  It subsequently saw settlement during the Early Medieval period, when it was probably one of the seasonal residences of the regional king of Dumnonia.  A castle was built on the site by Richard, 1st Earl of Cornwall in the 13th century, during the Later Medieval period.  It later fell into disrepair and ruin.

Supporting paragraphs: Castle Hill, Mere Richard, 1st Earl of Cornwall
Answer: Germany