This page focuses on the Spanish, Catalan and Portuguese languages, and covers some major collections in the Iberian Peninsula.
An organization of libraries of Spain has been working to create a unified searchable catalog of Spanish libraries, but the rare books collections may not always be integrated into collective catalogs like these. Similarly, WorldCat may or may not list all of the older materials held in various libraries, but it may provide a helpful first indication of where your materials may be found. Individual libraries usually still maintain their own catalogs, which are the most reliable source of information about their holdings. Even then, old and rare books may not be cataloged online.
If you're not sure what you're looking for, perusing printed bibliographies is a good place to start. More information on searching for texts can be found on the home page of this guide.
Searching online catalogs is the fastest way to find what you're looking for if you already know what it is. If you want to explore, browsing bibliographies may be the way to go. Many paper bibliographies are available under Z call numbers, and in facsimile editions via Google Books and HathiTrust. More information on bibliographies can be found on the home page of this guide.
Catalogs of Spanish and Portuguese printed books sometimes include both languages, as well as the other languages of the peninsula. They are generally divided by century, though some catalogs list incunabula and sixteenth-century books together as books printed before 1601. Selective bibliographies of books from the seventeenth century can be found, with titles chosen by genre, author, area of printing, and so on. Many catalogs of specific collections are also available. For example, the Regenstein Library holds a number of catalogs of comedias sueltas [plays printed in booklet form] from various libraries in Europe and the Americas.
The national libraries of Spain and Portugal have been the centralized book repositories of their respective countries since the eighteenth century, and are important centers of research for early printed books.
When requesting access to old and rare materials, most institutions will require that you apply for some sort of researcher's card and may require to see some evidence of why you need to use the materials. It is a good idea to anticipate this, and familiarize yourself with the requirements at the libraries you intend to visit before you travel. It is also advisable to bring an original letter from your department chair or dissertation advisor attesting to your research needs.
More information on visiting libraries and archives can be found on the home page of this guide.
In addition to the national libraries, the important historical universities and state institutions of Iberia also hold important collections. A number of private libraries and have smaller holdings that may prove to be invaluable in your research.
For libraries in North America with collections of early printed books, please see the Collections in North America page of this guide.