An organisation called FARO 1540, the Association for the Defence and Promotion of Environmental and Cultural Heritage of Faro, has submitted the request to the University of Oxford.
The group from the city of Faro in southern Portugal, says the books were looted by Robert Devereux, the Earl of Essex, in July 1596, from Faro’s Library of the Bishop of the Algarve.
In 1600, the earl gave the collection, consisting of 65 titles and 91 volumes, to his friend Thomas Bodley and the books have been in the Bodleian Library at Oxford University since 1602.
Bruno Lage, FARO 1540’s chairman, told the Oxford Mail: “We want the books back because they are part of our history, our heritage and our identity.
“They would be more valued in Faro and would be equally well preserved.
“In addition, these books can be displayed in one of the city’s museums as works of great symbolic, cultural and historical value.”
Bodleian Library spokeswoman Alison Prince said: “I can now confirm that we did receive this request and have responded to the sender directly.”
She refused to say whether the university will return the books.
Mr Lage added: “We are certain that the British authorities will recognise the justice of our claim and that will bring justice to a friendly country and a city that is proud of its ancient history and its contribution to European culture.”
This is not the first time a country has requested the return of a book collection from the famous Oxford library.
In August last year Ireland called for the return of one its oldest manuscripts, which is at the Bodleian.
The Annals of Inisfallen document the history of Ireland between AD 433 and 1450 and dates back to the 12th century.
They were inscribed in Irish and Latin and contain more than 2,500 entries.
Ireland’s Arts and Heritage Minister Jimmy Deenihan requested that the annals are returned so that they can be housed at Killarney House. Currently the manuscripts are still in Oxford.