[2] The Emperor Pedro II (1831–1889) laid the cornerstone of the building on 10 June 1880, and his daughter, Isabel, Princess Imperial of Brazil, together with her husband, the Prince Gaston, Count of Eu, inaugurated it on 10 September 1887.

The four statues that adorn it portray respectively Pedro Álvares Cabral, Luís de Camões, Infante D. Henrique and Vasco da Gama.

The hall also has a beautiful monument of silver, ivory and marble (the Altar of the Homeland), of 1.7 meters of height, that celebrates the time of the discoveries, realized in the Casa Reis & Filhos in Porto by the goldsmith António Maria Ribeiro, and acquired in 1923 by the Royal Cabinet.

Among the 350,000 volumes, both national and foreign, are rare works such as a copy of the "princeps" edition of Os Lusíadas of Camões (1572), the Ordinations of D. Manuel (1521), the Capitolos de Cortes and Leys (1539), Verdadeira informaçam das terras do Preste Joam, segundo vio e escreveo ho padre Francisco Alvarez (1540), a manuscript of the comedy "Tu, só tu, puro amor" by Machado de Assis, and many others.

[citation needed] The Royal Cabinet publishes the magazine Convergência Lusíada (semester) and promotes courses on Literature, Portuguese Language, History, Anthropology and Arts, destined mainly for university students.