Highclere Castle is a country house in high Elizabethan style, with park designed by Capability Brown. The 1,000 acre estate is in the English county of Hampshire, about a mile south of the border with Berkshire. It is the country seat of the Earls of Carnarvon; a branch of the Anglo-Welsh Herbert family.

The present castle stands on the site of an earlier house, in turn built on the foundations of the medieval palace of the Bishops of Winchester, who owned this estate from the 8th century. The original site was recorded in the Domesday Book. Since 1679, the castle has been home to the Carnarvon family. In 1692, Robert Sawyer, a lawyer and college friend of Samuel Pepys, bequeathed a mansion at Highclere to his only daughter, Margaret. Margaret was the first wife of the 8th Earl of Pembroke. Their second son, Robert Sawyer Herbert, inherited Highclere, began its picture collection and created the garden temples. His nephew and heir Henry Herbert was made Baron Porchester and 1st Earl of Carnarvon by King George III. In those years, the house was a square, classical mansion, but it was remodeled and all but rebuilt for the third earl by Sir Charles Barry in 1839 to 1842 after he had finished building the Houses of Parliament. It is in the "High Elizabethan" style and faced in Bath stone. The term "High Elizabethan" with which the house is often tagged refers to the English architecture of the late 16th century and early 17th century when traditional Tudor architecture was being challenged by the newly arrived Italian Renaissance influences. During the 19th century there was a huge Renaissance revival movement of which Sir Charles Barry was a great exponent. Barry had been inspired to become an architect by the Renaissance architecture of Italy and was very proficient at working in the Renaissance based style which in the 19th century became known as Italianate architecture. His work at Cliveden is considered amongst his finest. At Highclere, however he worked in the English renaissance revival style, but added to it many of the motifs of the Italianate style. This is particularly noticeable in the towers which are slimmer and more refined than those of the other great English Renaissance revival house Mentmore Towers built in the same era. This strong Italianate influence has led to the castle being quite fairly described as in the Italianate style. The external walls are decorated with strapwork designs and cornicing typical of Renaissance architecture. The Renaissance theme is evident within the castle. Curiously so in the great hall, which like that at Mentmore is modeled on an Italian Renaissance central courtyard, complete with arcades and loggias. However, in an attempt to resemble a medieval English great hall, Barry has mixed styles introducing to the Italianate effect a Gothic influence evident in the points rather than curves of the arches. This mixing of styles was particularly common in this period and would not have been found in a genuine Elizabethan house. Although the exterior of the north, east and south sides were completed by the time the 3rd Earl died in 1849 and Sir Charles Barry died in 1852, the interior and the west wing (designated as servants' quarters) were still far from complete. The 4th Earl turned to the architect Thomas Allom, who had worked with Barry, to supervise work on the interior of the Castle, which was completed on 1878. The 1st Earl rebuilt his park according to a design by Capability Brown during 1774 to 1777, relocating the village in the process (the remains of the church of 1689 are at the south west corner of the castle). The famous 18th century seed collector Bishop Stephen Pococke was a friend and brought Lebanon Cedar seeds from a trip to Lebanon. These beautiful trees can be seen in the garden today. Various follies and eye-catchers exist on the estate. To the east of the house is the Temple, a strange structure erected before 1743 with Corinthian columns from Devonshire House in Piccadilly. "Heaven's Gate" is an eye-catcher about 18 m high on Sidown Hill, built in 1731 from a design, it is thought, by the 9th Earl of Pembroke. It fell shortly afterwards. The event was witnessed and recorded by a Rev. J Milles, who recorded that "we had not been there above half an hour before we saw it cleave from ye foundations and it fell with such a noise yet was heard at three or four miles distant". The hybrid holly Ilex x altaclerensis (Highclere Holly) was developed here in about 1835 by hybridising the Madeiran Ilex perado (grown in a greenhouse) with the local native Ilex aquifolium.

The castle is home to an Egyptian Exhibition which was founded by the 5th Earl who, along with his archaeological colleague, Howard Carter, famously discovered the tomb of an Egyptian Boy Pharaoh Tutankhamun in 1922. The 5th Earl was an enthusiastic amateur Egyptologist, undertaking in 1907 to sponsor the excavation of nobles' tombs in Deir el-Bahari ( Thebes).

Visiting the castle
The castle is in-residence, meaning it is only open on certain dates. Highclere, the Gardens, and the Egyptology Exhibition are closed until Easter Opening which runs from Sunday, 17th of April to Tuesday, 3rd of May; 7 days a week. It then opens again with a Summer Opening from Sunday, 3rd July to Thursday, 1 September; open only Sunday to Thursday. When visiting, best bet is to check the website before heading out as dates are subject to change. Admission prices range from £4.00 - £15.00 depending on whether or not you want to visit just the Gardens, Castle, Egyptology Exhibition, or all three. Group rates and season passes are available.

Film and television
  • The saloon appeared in the film The Four Feathers starring Heath Ledger.
  • The exterior appeared as Lord Graves's house in the film King Ralph .
  • Totleigh Towers, in the TV version of Jeeves and Wooster , was represented by Highclere Castle.
  • Shots from both the interior and exterior are used as the imposing Mistlethwaite Manor in the Hallmark Hall of Fame's 1987 version of The Secret Garden .
  • It is the main setting for the British television period drama Downton Abbey , as a result of which The Tatler referred to the area around Highclere as "Downtonia".