Question: Mold Castle was erected under instructions from the Earl also known by what name?

Context paragraphs:
Mold Castle: Mold Castle (Welsh: "Castell yr Wyddgrug" ), on Bailey Hill in the town of Mold, Flintshire, Northeast Wales, is a motte-and-bailey castle erected around 1072, probably by the Norman Robert de Montalt under instructions from Hugh d'Avranches, Earl of Chester.  Little remains except the mound on which the motte was built.  It stands close to the 15th-century parish church, St Mary's Church near the centre of the town.

New Slains Castle: Slains Castle, also known as New Slains Castle to distinguish it from nearby Old Slains Castle, is a ruined castle in Aberdeenshire, Scotland.  It overlooks the North Sea from its cliff-top site 1 km east of Cruden Bay.  The core of the castle is a 16th-century tower house, built by the 9th Earl of Erroll.  Significant reconstruction of the castle has been carried out a number of times, lastly in 1837 when it was rebuilt as a Scots Baronial mansion.  At one time it had three extensive gardens, but is now a roofless ruin.  Plans to restore the castle have been on hold since 2009.

Northburgh Castle: Northburgh Castle, also known as Green Castle, is a ruined 14th-century castle near Greencastle, County Donegal, Ireland.  It was built in 1305 by Richard Óg de Burgh, 2nd Earl of Ulster.  Northburgh Castle was sited to control Lough Foyle, and was captured by Edward Bruce in 1316.  Walter Liath de Burgh was imprisoned in 1328 at the castle by his cousin William Donn de Burgh, 3rd Earl of Ulster, and died of starvation in February 1332.  William’s sister was found dead beneath the battlements.  After William's death, the castle became a stronghold of the O'Doherty family.  Northburgh Castle suffered considerable damage by cannon fire and eventually was left in ruins after the 17th century.

Piel Castle: Piel Castle, also known as Fouldry Castle or the Pile of Fouldray, is a castle situated on the south-eastern point of Piel Island, off the coast of the Furness Peninsula in north-west England.  Built in the early-14th century by John Cockerham, the Abbot of neighbouring Furness Abbey, it was intended to oversea the trade through the local harbour and to protect against Scottish raids.  The castle was built using stones from the local beach, and featured a large keep with surrounding inner and outer baileys.  It was used as a base by the Yorkist pretender Lambert Simnel in 1487, but by 1534 it had fallen into ruin and passed into the hands of the Crown.  Sea erosion began to cause significant damage to the castle in the early 19th century.  In the 1870s the castle's owner, the Duke of Buccleuch, carried out extensive restoration work and erected outworks to protect it against further damage from the sea.  In 1920 the castle was given to the town of Barrow-in-Furness and is now in the care of English Heritage.

Lieber Code: The Lieber Code of April 24, 1863, also known as Instructions for the Government of Armies of the United States in the Field, General Order № 100, or Lieber Instructions, was an instruction signed by US President Abraham Lincoln to the Union Forces of the United States during the American Civil War that dictated how soldiers should conduct themselves in wartime.  Its name reflects its author, the German-American legal scholar and political philosopher Franz Lieber.

Hugh d'Avranches, Earl of Chester: Hugh d'Avranches (  1047  – 27 July 1101), also known as Hugh the Fat (French: "Hugues le Gros" ) or Hugh the Wolf (Latin: "Hugo Lupus" ), was the second Norman earl of Chester (2nd creation) and one of the great magnates of early Norman England.

Milntown Castle: Milntown Castle was an early 16th-century castle which was situated near Milton, in Easter Ross, in the Scottish Highlands.  It was built by the Munro of Milntown family, a cadet branch of the Clan Munro.  In 1656, the castle and estate was sold to George Mackenzie, 1st Earl of Cromartie also known as George MacKenzie of Tarbet.  He renamed the estate New Tarbat after Tarbat Castle (now more commonly known as Ballone Castle), the family's original seat near Portmahomack.  Mackenzie had the Milntown Castle pulled down and only part of the basement survives.  He then replaced the castle with a new mansion built nearby.  When the new mansion was built, the old Milntown Castle was remodelled as part of the garden.  That mansion was itself demolished and in 1787 was replaced with a Georgian house (now known as Tarbat House) by his descendant John Mackenzie, Lord MacLeod.

Antrim Castle: Antrim Castle also known as Massereene Castle was a castle in Antrim, County Antrim, Northern Ireland, on the banks of the Sixmilewater River.  It was erected in stages between 1613 and 1662.  It was destroyed by fire in 1922 and finally demolished in the 1970s.  All that remain are a slightly raised grassed platform as well as a freestanding Italian stair tower which was built in 1887 and a gatehouse, which was built around 1818 with twin neo-Tudor towers, with older connecting walls.  The gardens are a popular tourist attraction on the Randalstown Road, Antrim.

Niedzica Castle: Niedzica Castle also known as Dunajec Castle (, Hungarian: "Nedec Váralja / Nedec-Vár" , German: "Sub-Arx Unterschloss" , Slovak: "Nedecký hrad" ), is located in the southernmost part of Poland in Niedzica (Nowy Targ County in Lesser Poland).  It was erected between the years 1320 and 1326 by Kokos of Brezovica on the site of an ancient stronghold surrounded by earthen walls in the Pieniny mountains.  The Niedzica Castle stands at an altitude of 566 m, on a hill 300 m upstream from the Dunajec River mouth, measured from the center of the dam on Lake Czorsztyn.  The outline of Niedzica Castle can best be viewed from the ruins of Czorsztyn Castle on the other side of the lake.  It is known as one of the most picturesque castles in the country and adorns the covers of many books.

Elmina Castle: Elmina Castle was erected by the Portuguese in 1482 as São Jorge da Mina ("St. George of the Mine") Castle, also known simply as "Mina" or "Feitoria da Mina") in present-day Elmina, Ghana (formerly the Gold Coast).  It was the first trading post built on the Gulf of Guinea, so is the oldest European building in existence south of the Sahara.  First established as a trade settlement, the castle later became one of the most important stops on the route of the Atlantic slave trade.  The Dutch seized the fort from the Portuguese in 1637, and took over all the Portuguese Gold Coast in 1642.  The slave trade continued under the Dutch until 1814; in 1872, the Dutch Gold Coast, including the fort, became a possession of the British Empire.

Supporting paragraphs: Mold Castle Hugh d'Avranches, Earl of Chester
Answer: Hugh the Fat