The largest part of the documentation contained in the AHPAL is made up of the collection of deeds signed before notary in the province of Alava. It currently contains more than thirteen thousand deeds, dating back to 1502 and increasing year-on-year with the inclusion of new hundred-year-old deeds. The most recent are from 1906.
All other documentation that arrived mixed in with the notarial documentation was separated from this initial collection and later additions. This organisation enabled us to identify:
- The Ocio-Salazar Family Archive, an example of a noble Alava family distinguished with mercedes enriqueñas (special regional privileges), which would be linked to the other great families of the Modern Age. This collection was conserved by the scribe of Llodio (1853-1897), Mr. Francisco de Salazar.
- Documentation from the Municipal Courts, including rulings made by town and city Mayors under common jurisdiction in “no hermandad" (lit. non fraternity) cases, and whose rulings could be appealed against at the Chancery of Valladolid.
- Thoroughbred Files of great importance in proving the nobility awarded to all people from Alava from birth by Alfonso XI in 1332.
- The collection from the Higher Notary's Office for Royal Revenue for the District of Cantabria, was drawn from those notaries who worked both as public notaries in Vitoria and for the Royal Revenue.
- The correspondence of the Presidents and Secretaries of the Real Sociedad Bascongada de Amigos del País (Royal Basque Society of Friends of the Nation) from 1770 to 1792
- The collection from the Oñate University in Vitoria: founded by Rodrigo Mercado de Zuazola in 1515 and transferred to Vitoria in 1834.
- The collection form the Literary University in Vitoria, created by the City Council under the auspices of the 1868 Ley de Enseñanza Libre (Education Deregulation Act).
The Mortgage Registry collection was added to the AHPAL's original core collection in 1949. This institution was originally created by Carlos III to register real estate transactions and leasing, and in 1862 became today's Property Registry.
Until 1976, when the Archive was transferred to the Casa de Cultura, new documentary collections could not be included, in spite of Decree 914/1969 which transformed the Provincial Historical Archives in the intermediate-level archives for the Central Government, and thus, made them responsible for gathering all documentation generated by government bodies outside the capital.
- Documentation from the provincial offices of the National Statistics Institutes and the Treasury, which included important disentailment documentation.
- Other collections from institutions set up under General Franco and which no longer operate: Vertical Unions (AISS), Radio Alava (part of the network of the Movimiento Nacional radio stations), the Provincial Office for Family Affairs and the Women's Institute.
- In 1993, periodic transfers began, incorporating documentary collections from Provincial Offices for Culture, Public Works and Agriculture; three years later, the collections from the Government Office in Alava, Legal Services and Civil Protection were added.
The AHPAL has also grown thanks to the Office of National Archive's purchase of some private collections, such as that of the Gámiz family (1451 - 1870) from Alava, featuring letters from Fernando I, King of the Romans, Hungary and Bohemia to his ambassador in Spain, Mr. Alonso de Gámiz; and the purchase of the a collection of Basque Country Post Cards.
Finally, in 1997, Mariano Belestá's private collection was donated. He was a general under Queen Isabel and married Fausta Elío of Vitoria, niece of the Carlist General Elío. This collection is complemented by the documentation deposited in the Vitoria Diocesan Seminary Library.
Collections that have disappeared. As mentioned above, the fact that the Archive was not originally housed in a building suitable for its needs and the lack of trained personnel have had a significant impact on the document collection over the years: this situation was further hindered by the break out of the Civil War and a general lack of interest in the protection of documentary heritage. These circumstances led to the loss of certain documentary collections, considered of importance for the history of Alava:
- Parts of the Notarial documents from Laguardia and the Mortgages Registry Books, both of which were stored in the public jail, and in the end were burned during the Civil War.
- A large part of the Notarial documents from the Ribera Alta area, discarded by the local City Council during reformation work.
- Provincial Court Documentation, sold by the kilogram as scrap paper during the 1940s. With it, proof of the Alava Regional Council's jurisdictional role would also disappear.
- A large part of the Civil Government's and the Movement's Provincial Offices' documentation.
This, in practice, has meant the almost total disappearance of the documentation generated by the National Government in the province of Alava during the entire 19th and almost two thirds of the 20th century.