Prosiect Penrhyn is one of ISWE’s core initiatives. It brings together a vibrant regional network of cultural heritage, community, business and academic partners to generate enhanced engagement with the local and global history of the Penrhyn estate.
From the time of its emergence in the medieval period through to the early part of the twentieth century, the Penrhyn estate was dominant force in the life of north west Wales. This influence extended across a massive landholding base and embraced all aspects of society – ranging from industry, politics, culture and religion through to architecture, language, farming and land management. The story and legacy of Penrhyn is complex and multifaceted, both intensely local and international in scale – and infused with important strands of considerable controversy and contention, notably the centrality of the transatlantic slave trade to the estate’s history and its essential role in the global history of slate, including the Great Penrhyn Quarry Strike of 1900-03.

Penrhyn has been central to the history, landscapes and identity of north west Wales since the medieval period, yet remains conspicuously underexplored. Prosiect Penrhyn has been established by ISWE in recognition that Penrhyn offers an outstanding prism for exploring the history of the region, its communities and links to the wider world. The programme of research generated by Prosiect Penrhyn has the potential to be transformational: interrogating established narratives, questioning traditional perceptions and myths and providing rigorous interpretation which offers a step change for understandings of, and engagement with the local history, culture, landscapes and identity of Gwynedd.
The initiation of Prosiect Penrhyn was underpinned by the completion of a major cataloguing project at ÑÇÖÞÉ«°É Archives and Special Collections (BUASC), which facilitates access to the full corpus of records generated by the Penrhyn families and estate for the first time. The project also dovetails with two important allied initiatives which promise to make far reaching contributions towards the development and promotion of the region’s heritage, culture, tourism and economy, namely the Llechi Cymru | Wales Slate UNESCO World Heritage Bid and the National Trust’s strategy for transforming the way that the story of Penrhyn Castle is presented to the public through the interlinked areas of heritage interpretation, visitor experience and community engagement.
The Penrhyn Estate Archive

Penrhyn Castle is a major National Trust property located on the outskirts of ÑÇÖÞÉ«°É. For centuries it was the powerbase of one of the largest and most influential landed families and estates in Wales.
The Penrhyn Estate Archive is a continuous series of records created by the estate and its successive owners: the Gruffydd, Williams, Pennant and Douglas-Pennant families, between the thirteenth and twentieth centuries. It was one of the largest estate archives obtained by ÑÇÖÞÉ«°É Archives and Special Collections during the mid-twentieth century, initially through a major deposit in March 1939, with significant accruals in February and September 1966 and in 1999.
At the end of the nineteenth century, the Penrhyn estate extended to about 72,000 acres, making it the third largest in Wales. From the time of its emergence in the medieval period, it constituted a dominant force in the life of north west Wales, extending across a massive landholding base and exerting profound impacts on all aspects of society, ranging from industry, politics, culture and religion, through to architecture, language, farming and landscape. The archive contains records relating to all of the above – in its scope and extent it is unrivalled amongst the estate archives at ÑÇÖÞÉ«°É.
The majority of the records relate to the acquisition, consolidation, management and inheritance of the estate – title deeds, settlements, rentals, accounts, correspondence, maps and surveys. However, the history, character and legacy of Penrhyn is complex and multifaceted, including themes and episodes of considerable significance, controversy and contention. It is these features which provide the Penrhyn archive with its standout heritage and research value, as a collection of local, national and global significance, including:

- Records which detail the early development of a landed estate in north Wales beyond the traditional confines of the native system of landholding and inheritance (known as cyfran), including numerous examples of conve