The origins of the Regional Library of Bizkaia can be found in the personal library of Fidel de Sagarminaga, a politician, writer and owner of an outstanding library of nearly 12,000 titles, comprising historical works, national and foreign literary works, works on Basque themes, pamphlets and foreign journals. After his death on 21 March 1894, his heirs donated his magnificent library collection to the president of the Regional Government of Bizkaia.

At the time of this significant donation, the Regional Government did not, strictly speaking, have a library, and the collections therefore had to be housed in the Government’s headquarters, located in Bilbao’s Plaza Nueva. In February 1890, the Government had purchased an undeveloped plot of land on the Gran Vía, on land owned by the Arbieto lineage of Orduña, for the construction of the new Regional Government Building. The project envisaged an ambitious public building with areas for a Printing House, Archive and Library. Under the direction of the San Sebastian architect Luis Aladrén, the works took 10 years to complete, and the new Regional Government headquarters were inaugurated on 31 July 1900, the feast of St Ignatius.

Initially, Sagarminaga’s library was placed on the top floor of the new building, however, the difficulty of access made it advisable to relocate the collections to the ground floor. After several rehabilitation projects, which concluded in February 1907, the provincial library eventually consisted of three spacious rooms: one for works on Basque themes, and two for general works. There, Carmelo de Echegaray, Chronicler of the Basque Provinces, took up the task of sorting through the papers, recording and cataloguing books and manuscripts, ultimately organising the archive and library, which, 13 long years after its donation, was finally made available to scholars, researchers and the general public. However, the complexities of Bizkaia’s administrative life led to a rapid saturation of the building’s rooms, including those used as the library and archive. It was therefore a matter of urgency to remedy the situation. In 1921, the decision was made to commission the drafting of a project that, by modifying the building purchased the previous year by the Regional Government at the rear of the Government Headquarters, would create a Provincial Archive, Library and Printing House. This building, built at the end of the 19th century, had several different uses before becoming a library. From 1893, it housed the Bilbao Polytechnic Academy, and towards 1902, the San Fernando Academy. Both institutions were assigned to the Bilbao Secondary School and the Bilbao High School of Commerce, where they provided primary and secondary education and business and nautical studies, and prepared students for admission to the School of Industrial Engineering. In December 1914, part of the building was leased to the Círculo de Bellas Artes y Ateneo de Bilbao (the Bilbao Fine Arts Association and Athenaeum). The newspaper El Liberal is also known to have had its headquarters there between 29 March 1915 and 6 November 1921, when it relocated to Obispo Orueta street.

In its meeting of 19 December 1921, the Regional Government approved the project submitted by architect Juan Carlos Guerra for the total renovation of the building and conversion into Library, Archive and Printing House. Many difficulties were encountered during the construction work, which was not completed according to schedule. In May 1924, even Guerra complained that the premises under renovation were still occupied by the Athenaeum (which opened its new headquarters at Hotel Carlton on 4 January 1925), and by the Provincial Savings Bank and the Security Forces, provisionally located in the building. The official inauguration took place on 22 August 1929. A year earlier, on 27 August 1928, the Archive and Library Commission had decided to have the rear of the building turned into new headquarters for the Bizkaia Conservatorium of Music. Starting from the 1929-1930 academic year, the Conservatorium was already operating at the new building.

At the time of its inauguration, the Library collection comprised 18,000 titles, perfectly sorted and catalogued, and divided into two sections, namely, the general section and the Basque section. This division dates back from the first set of regulations produced in 1907, and the reasons alleged for this were that the library had been created for the collection of one of the most erudite Basque writers, a member of the Government of Bizkaia, and with the purpose of making research easier for Spanish researchers. In 1909, a Catalogue of authors compiled by Darío de Areitio, the first Archive and Library director, was published for the Basque section. Areitio himself described the new Library in these words: The building consists of a basement containing repeated works; the ground floor that serves as a book deposit; the first floor, containing the catalogue room and reading room at the disposal of the public; the second floor where the Historical Archive is located as well as four offices for researchers requiring books and documents, so that at the end of the day, they may leave all their materials on the desks and return the key. The next two floors up house the Administrative Archive. The building also featured a book binding department and a photographic laboratory.

In 1965, a large room with beautiful windows looking out onto Rodriguez Arias St. was arranged for students to use. The study room was extended and then in 1988 moved to the premises that had been occupied by the print shop (which had moved the previous year). The new room had two floors: the ground floor had individual work tables and the second floor, which was like a corridor, had space for group projects. In April 1988, the Library and the Archive were separated, and the latter was moved to a new building located in María Díaz de Haro street. The Library, bursting at the seams due to lack of space, and outdated in its services, underwent a new overhaul, extension and conversion of the physical space; however, the continuous growth of the rich bibliographical and newspaper collections of the Regional Library once again pushed the facility to the limit of its capacity. As a consequence, starting on 30 October 2003, an ambitious project for the extension and upgrading of the building was undertaken under the direction of IMB architects. The result was a Library adapted to the cultural reality of Bizkaia, providing new services to meet the challenges posed by the society of the 21st century.