History of Penrhyn Castle and Garden

Building the Castle 

The Penrhyn estate dates to the 12th century, with lands held by Ednyfed Fychan (d. 1236), Seneschal to Llywelyn the Great (1173–1240). By the 15th century, his descendant Gwilym ap Griffith (d. 1431) had built a hall house arranged around one or two courtyards on the site. 

In the 1780s, Richard Pennant (1739–1808) commissioned architect Samuel Wyatt to remodel this structure as a Gothick villa. But it was his heir, George Hay Dawkins-Pennant (1764–1840), who envisioned something far grander. 

In the 1820s, Dawkins-Pennant hired Thomas Hopper to design a vast new castle in the Norman Revival style. Drawing on medieval military architecture - arrow slits, battlements, massive walls - Hopper created not a defensive stronghold, but a theatrical display of power and wealth. 

Built using Anglesey’s Penmon limestone, encasing a brick core, the project incorporated ornate plasterwork and wooden carvings, and stained glass by Thomas Willement, a leading designer of the time. 

Construction took many years and cost a staggering £123,000 - equivalent to over £100 million today. Princess Victoria visited in 1832 and found it still unfinished. 

Though some critics mocked its pretend medievalism, calling it stage-set architecture, Penrhyn remains Hopper’s crowning achievement and a showcase of regional craftsmanship and materials. 

Human Costs 

Behind the castle’s splendour lies a brutal history. Between the 1500s and 1834, about twelve million Africans were forcibly transported to work on plantations in the Americas; perhaps a quarter died during the journey. In the 17th century, Gifford Pennant (d. 1676/7) established plantations in Jamaica. By 1805, his descendants were operating estates that enslaved hundreds. 

Although Gifford’s descendant Richard Pennant never visited Jamaica, he managed his plantations and enslaved workforce through meticulous correspondence from his Penrhyn home. A Member of Parliament and chairman of the pro-slavery West India Committee, he was a vocal opponent of abolition. 

When slavery was abolished in 1834, only children under six were freed immediately. Others were bound in forced “apprenticeships” until 1838. Compensation went not to enslaved people but to their captors: George Hay Dawkins-Pennant received £14,683 (around £18 million today) for 764 people. 

Across Britain, slaveholders received £20 million in government compensation - equivalent to £24 billion today - a debt not fully repaid until 2015. 

 

Garden 

Penrhyn’s grounds are as carefully crafted as its architecture. A 1768 map shows modest enclosures, likely including a kitchen garden. By 1841, sweeping lawns, curving paths, and specimen trees had transformed the grounds in the English landscape style. 

Victorian plant hunters added rhododendrons, fuchsias, and Asiatic exotics, while native oaks, ashes, and sycamores were arranged to frame views of Eryri (Snowdonia). A Wellingtonia, planted in 1839, now soars 46 metres above the terrace. 

Walter Speed (d.1921), head gardener for nearly six decades, developed productive gardens and ornamental features - including the famed 100-metre-long Fuchsia Arch built in the 1880s. Country Life magazine called it “the real glory of Penrhyn.” An acknowledged expert of his time, Speed managed a team of up to thirty gardeners. Today, a dedicated but much smaller crew continues to develop the gardens’ legacy. 

Enterprise 

Before the castle was transformed, the Pennants had already begun reshaping North Wales through estate improvements and industrial enterprise. Slate quarrying in the Bethesda area dates to the 15th century, but Richard Pennant's 1781 inheritance enabled the consolidation of smaller pits into the massive Penrhyn Quarry. 

He invested heavily in infrastructure: roads, a railway, and a deep-water port at Port Penrhyn, enabling exports on a global scale. 

By the early 19th century, Penrhyn had become the world’s largest slate quarry, employing nearly 3,000 men. A 1793 wartime export tax briefly disrupted production, but Pennant redirected the workforce to construct tramways and “galleries” carved into the quarry’s sides. Output recovered by 1802. 

Strike 

Slate quarrying was dangerous, arduous and poorly paid compared to the riches it generated. Workers began organising in 1865, and by 1874 had formed the North Wales Quarrymen’s Union following a short strike. 

Tensions escalated under George Sholto Douglas-Pennant (1836–1907), who broke with earlier agreements. A lockout in 1896–97 triggered the Great Strike (1900–1903) - a three-year standstill involving over 2,800 workers. Many left the region permanently. Those who remained faced ruin or returned under punishing new terms. 

The rift between strikers and strike-breakers - ‘y bradwyr’ - left social divisions that endured for generations and continue to shape local memory. 

Cultural Landscape 

The slate industry reshaped the physical and cultural landscape of North West Wales. In 2021, UNESCO recognised this legacy by designating the region - including Penrhyn Quarry - as a World Heritage Site. 

Penrhyn Quarry pioneered technologies such as water-powered inclines, advanced drainage systems, and the first circular stone saws - innovations growing from colonial wealth and industrial ambition. 

Quarry life also nurtured Welsh-language culture. The caban, a communal hut for meals, became a centre for debate, poetry, song and Eisteddfod competitions - embedding slate-mining in local heritage. Welsh slate roofs still cap buildings around the world, a legacy of labour and cultural identity. 

 

Collection 

Penrhyn Castle boasts a significant collection of historic furnishings, artworks, and decorative objects reflecting its 19th-century neo-Norman grandeur. Much of the furniture was designed by architect Thomas Hopper and crafted by estate carpenters, with intricate oak carvings seen in tables and chairs. The striking one-ton slate bed is a reminder of Penrhyn’s ties to the slate industry.  

Luxurious textiles, with some carpet designs also attributed to Hopper, Minton ceramics, Chinese export porcelain, and silver by Paul Storr further enhance the sumptuous interior.  

The visual art collection is equally impressive, featuring works by celebrated artists such as Antonio Canaletto and Thomas Gainsborough. Portraits of family members and historical figures, including works by Sir Joshua Reynolds, Allan Ramsay and Mary Beale, convey a sense of lineage and prestige. Most striking, however, is the extensive landscape collection, which features evocative paintings by Richard Wilson, Aert van der Neer, and a commanding view of Penrhyn Slate Quarry by Henry Hawkins. Together, these elements form a cohesive and immersive environment that not only complements the castle’s architecture but also reflects the Pennant family's wealth, global connections, and industrial legacy. 

A developing story 

Penrhyn Castle’s story is still being written. The National Trust is continuing to research the estate’s complex past, working with academics, communities, and international collaborators. Together, they are uncovering a fuller narrative - one that both recognises the artistry and acknowledges the injustice at its heart. 

Further Reading

• Legacies of British Slavery 

• Slave Voyages 

• Llechi Cymru (Slate Wales) World Heritage Site 

• Strike! Virtual Workshop 

• Penrhyn Estate Archive (Jamaica)