The genealogical research in Spain must be taken through the study of different documents, among them:

• Birth, marriage and death certificates.
• Baptism, marriage and last rites registration certificates.
• Wills.
• Law suits, judicial processes and sentences.
• Transaction deeds, buying and selling title deed.
• Partitions and the division of wealth, renting and leasing, donations.
• Documentation concerning "Mayorazgos", Benefits and the Seizure of Possessions.
• Nominations, Titles related to Positions, Dignities and Honorific Posts.
• Grants and Powers.
• Letters on the Creation and Succession of Titled Nobility.
• Bulla Seals, Matrimonial Capitulations.
• Regal Provisions.
• Accounts, Business Dealings, Powers, Requisitions.
• Certificates on the concession of Coats of Arms.
• Pleads and Executory of "Nobility and Bloodline Purity".
• Letters and Private Correspondence.
• Articles in different publications.
• Photographs.