Flintshire's historic St Deiniol's Library is changing its name to honour its benefactor, William Ewart Gladstone.
Gladstone's Library, Hawarden, is taking the name in recognition of the Victorian's achievements, including becoming prime minister four times.
Today, the residential library houses 250,000 books, of which 32,000 were donated by the statesman himself.
Library warden Peter Francis said the name change was a fitting tribute.
"You can spend years in the library and get very little impression of a 5th Century Celtic Christian called Deiniol," he said.
"But spend just a couple of minutes at the library and you immediately get a sense of Gladstone.
"This is not just because of all the Gladstone portraits and busts but because his spirit permeates the place."
Gladstone's home and estate is just across the road from the library which he founded.
Originally, it was a tin building but following his death in 1898, the library became the national memorial to Gladstone, and was opened in 1902.
Gladstone is said to have read 20,000 of the books he donated, and his annotations can still be found on many pages.
The books cover history and politics, classical and contemporary culture, theology and religious studies, attracting researchers from around the world.
While much is known and has been written about Gladstone, the contrary can be said about Saint Deiniol who died in the late 500s, and was the first bishop of Bangor.
Hawarden church is dedicated to the saint and that may be the reason the library originally took the name.
The late former Archbishop of Canterbury, Lord Robert Runcie once described a visit to Gladstone's library.
"To stand amidst the books in the library is an intimidating experience for it is an encounter with the restless, brooding intelligence that was William Ewart Gladstone," he said.