Windsor Castle, nestled in Berkshire, England, is more than just a regal abode; it’s a living chronicle of nearly a millennium of architectural evolution, intimately connected with the English and British monarchy.

Its origins trace back to the 11th century, when William the Conqueror commissioned the original fortress following the Norman conquest of England. From the time of Henry I (1100–1135) onwards, Windsor Castle has been a favored residence for reigning monarchs, boasting the prestigious title of Europe’s longest-occupied palace.

The castle’s opulent state apartments, crafted in the early 19th century, are hailed by art historian Hugh Roberts as unparalleled expressions of Georgian aesthetic refinement. Enclosed within the castle’s walls, St George’s Chapel, erected in the 15th century, is celebrated by historian John Martin Robinson as a masterpiece of English Perpendicular Gothic architecture.

The extensive grounds of Windsor Castle span 13 acres (5.3 hectares), blending the features of a fortress, a palace, and a small township. Its current layout is the result of various building endeavors carried out over time, including significant reconstruction following a fire in 1992. While predominantly reflecting Georgian and Victorian styles, the castle’s medieval core is evident, complemented by Gothic elements reimagined with a contemporary twist.

Since the 14th century, Windsor Castle’s architecture has sought to reinterpret older styles and traditions in a modern context. This often involved mimicking outdated or antiquated architectural fashions. Architect Sir William Whitfield observed a “certain fictive quality” to the castle’s architecture, with its Picturesque and Gothic elements creating an illusion of a theatrical stage. Despite efforts in the late 20th century to unveil more of the original structures for authenticity, there remains a lingering sense of drama and spectacle.

At the heart of Windsor Castle lies the Middle Ward, a courtyard embracing the central man-made hill called the motte. Rising 50 feet (15 m) tall, this mound is constructed from chalk excavated from the surrounding ditch. At its summit sits the Round Tower, also referred to as the keep, inspired by an original 12th-century design. In the early 19th century, architect Jeffry Wyatville augmented the tower’s height by an additional 30 feet (9.1 m), enhancing its imposing stature.

Between 1991 and 1993, the interior of the Round Tower underwent renovations to accommodate the Royal Archives. This involved creating new space within the hollow extension constructed by Wyatville. Despite its name, the Round Tower isn’t perfectly cylindrical, owing to the shape and composition of the underlying motte. Some critics argue that its current height is disproportionate to its width. Archaeologist Tim Tatton-Brown, for instance, views it as a modification of the original medieval structure rather than a faithful reconstruction.

The Upper Ward of Windsor Castle showcases prominent structures enclosed by the upper bailey wall, forming a central quadrangle. On the north side, you’ll find the State Apartments, while various buildings line the east wall. Positioned to the south are the private royal apartments, the King George IV Gate, and the Edward III Tower, with the motte and Round Tower marking the western boundary. Adding to the grandeur of the ward is a bronze equestrian statue of Charles II beneath the Round Tower, crafted in 1679 by Josias Ibach and adorned with carvings by Grinling Gibbons.

Adjacent to the Upper Ward are the North Terrace, offering scenic views of the River Thames, and the East Terrace, overlooking the Home Park. These terraces, designed by Hugh May in the 17th century, feature a private formal rose garden on the East Terrace, initially planned by George IV in the 1820s. This garden underwent renovations by Prince Philip, Duke of Edinburgh, after serving as a victory garden during World War II, with Princesses Elizabeth and Margaret also tending to it. In a noteworthy move, the garden was opened to the public in 2020 after being accessible to only a select few for 40 years.

The State Apartments dominate the northern side of the Upper Ward, forming a central component of the quadrangle. This modern building follows the medieval footprint laid down by Edward III, with the ground floor housing service chambers and cellars, while the grander first floor serves as the main part of the palace. The layout of the western end of the State Apartments on the first floor is largely attributed to architect Hugh May, while the eastern side reflects Jeffry Wyatville’s designs.

Below and to the west of the Round Tower lies the Lower Ward, accessible via the Norman Gate. Initially featuring medieval architecture, significant renovation and reconstruction took place during the mid-Victorian period under the guidance of Anthony Salvin and Edward Blore, resulting in a unified Gothic composition. Within the Lower Ward, notable landmarks include St George’s Chapel and the majority of buildings associated with the Order of the Garter.

Because of Windsor Castle’s perch on steep terrain, the castle grounds are somewhat limited in size. Stretching eastward from the Upper Ward is a garden featuring a 19th-century terrace. Surrounding the castle is expansive parkland, with the area east of the castle known as the Home Park—a creation of the 19th century. Home Park includes parkland, two operational farms, estate cottages primarily for employees, and the Frogmore estate.

Running south of the castle is the Long Walk, a broad avenue lined with trees, stretching 2.65 miles (4.26 km) and spanning 240 ft (73 m) in width. Initially planted with 17th-century elms, these were later replaced with alternating chestnut and plane trees due to the devastating effects of Dutch elm disease, prompting extensive replanting efforts after 1945.

The construction of Windsor Castle was initiated by William the Conqueror in the decade following the Norman conquest of 1066. As part of a defensive strategy, William established a network of motte and bailey castles around London, strategically positioned within a day’s march of each other, roughly 20 miles (32 km) apart. Windsor Castle played a crucial role in this defensive ring due to its proximity to both the River Thames—an important medieval route to London—and Windsor Forest, a royal hunting ground previously utilized by Saxon kings. The nearby settlement of Clivore, or Clewer, also had historical significance as an ancient Saxon residence.

The earliest incarnation of Windsor Castle was constructed from wood, featuring a keep positioned atop a man-made motte, or mound, protected by a modest bailey wall. Situated on a chalk bluff rising 100 ft (30 m) above the river, the castle commanded a formidable defensive position. East of the keep, a second wooden bailey was erected, evolving over time into the Upper Ward. By the century’s end, a third bailey had emerged to the west, establishing the foundational layout of the castle as we know it today. In its design, Windsor Castle bore a resemblance to Arundel Castle, another sturdy Norman stronghold, while its double bailey layout echoed features seen in Rockingham and Alnwick Castle.

Construction projects initiated by King John focused primarily on improving accommodations rather than fortifications at Windsor Castle. The castle gained significance during the English barons’ revolt, enduring a siege in 1214. In 1215, John used the castle as his base for negotiations leading to the signing of Magna Carta at nearby Runnymede. Subsequently, in 1216, the castle faced another siege by baronial and French forces under the command of the Count of Nevers. However, John’s constable, Engelard de Cigogné, effectively defended the castle during this period.

Windsor Castle played a significant role during the reign of Edward III, who was actually born there. In 1344, he announced plans to establish the Order of the Round Table at the castle and began constructing a new building for this purpose. However, this ambitious project was never completed. It was described as a round structure, roughly 200 ft (61 m) in diameter, likely intended to occupy the center of the Upper Ward. Shortly afterward, Edward shifted his focus to founding the Order of the Garter, with Windsor Castle serving as its headquarters, providing lodging for the Poor Knights of Windsor.

In the process, Edward embarked on a reconstruction of Windsor Castle, particularly Henry III’s palace, aiming to create a symbol of royal power and chivalry. Inspired by his grandfather Edward I’s military achievements and concerned about the weakening of royal authority under his father, Edward II, Edward III sought to create a new architectural vision—one that was innovative, aesthetically pleasing, robust, and martial in nature.

Throughout the 15th century, despite mounting political turmoil, Windsor Castle remained a favored residence for monarchs. In 1399, during his usurpation, Henry IV seized the castle but failed to capture Richard II, who had fled to London. Under Henry V’s reign, the castle hosted a significant diplomatic event in 1417—a visit from the Holy Roman Emperor—which pushed the castle’s accommodations to their limits.

Henry VIII cherished Windsor Castle, indulging in various pastimes during his youth, such as shooting, singing, dancing, wrestling, and playing musical instruments. The tradition of Garter Feasts continued under his reign, becoming increasingly lavish and prompting restrictions on the size of the royal entourage due to swelling numbers. During the Pilgrimage of Grace—a major uprising in the north against Henry’s authority in 1536—the king relied on Windsor as a secure base in the south to oversee his military response. Throughout the Tudor period, Windsor served as a safe haven during outbreaks of plague in London.

James I, on the other hand, primarily used Windsor Castle for hunting, one of his favorite pursuits, and for socializing with friends. These gatherings often involved prolonged drinking sessions, with a particularly notorious occasion in 1606 featuring Christian IV of Denmark, resulting in scandalous behavior that became infamous throughout Europe. The limited space at Windsor frequently led to disputes over accommodations between James’ English and Scottish retinues.

George I and George II didn’t show much interest in Windsor Castle, preferring other palaces such as St James’s, Hampton Court, and Kensington. Apartments in the Upper Ward were often granted as privileges of “grace and favour” to prominent widows or friends of the Crown. The Duke of Cumberland, who served as the Ranger of Windsor Great Park, frequently utilized the property. By the 1740s, Windsor Castle had become an early tourist attraction, with affluent visitors paying the castle keeper for admission, marveling at oddities like the castle’s narwhal horn. Guidebooks to Windsor became available in the 1750s, with publications by George Bickham in 1753 and Joseph Pote in 1755. As the State Apartments deteriorated, even the general public gained regular access to the property.

In 1820, George IV became king with the ambition of establishing luxurious royal palaces that reflected his stature as the leader of a growing Britain. Despite costly extensions to his earlier residences, Carlton House and the Brighton Pavilion, they remained inadequate for grand court events. As Prince Regent, George expanded the Royal Lodge in the castle park, and upon his ascension to the throne, he launched an extensive modernization program for Windsor Castle itself.

When Edward VII took the throne in 1901, he energetically pursued the modernization of Windsor Castle. Rooms in the Upper Ward underwent significant decluttering and redecoration for the first time in many years, with Edward personally overseeing the process. He introduced electric lighting and central heating to more rooms, installed telephone lines, and built garages for the newly invented automobiles. The 1908 Olympics saw the marathon start from Windsor Castle, and in 1911, pioneering aviator Thomas Sopwith achieved the historic feat of landing an aircraft at the castle for the first time.