Among the holdings of The National Library of Wales there are several hundred archives, some of them created by prominent individuals, others created by institutions, societies and national bodies.

They relate to a wide variety of subjects relating to Wales and the Celtic countries – history, literature, religion and politics in particular – and range in date from the Middle Ages to the present day.

Archives do not consist solely of writing on paper and parchment, but also comprise printed material, photographs, maps, sound recordings and electronic records.