In this reference, Buffery and Marcer cover all of the areas historically inhabited by the Catalan people. These are, in order of size and population: Catalonia, which accounts for over half of the population of the Catalan-speaking areas; Valencia, with over a third; the Balearic Islands with just under 8 percent; and the Catalunya Nord, the Principality of Andorra, and the Catalan-speaking areas within Aragon, Murcia, and Alghero.

The Historical Dictionary of the Catalans deals not only with the people who live in Catalonia, but with the language and culture of the Catalan countries as well. This is done through a chronology, an introductory essay, a bibliography, and over 600 cross-referenced dictionary entries on significant persons, places, events, institutions, and aspects of culture, society, economy, and politics.