[1] The means used by the students to limit access only to nobles was to require "cleanliness of blood", which seemed designed to prevent the entry of descendants of Jewish converts but in reality prevented the entry of humble aspirants, who had no family records to prove their cleanliness of blood.

For lower-class students, often servants of the nobles, an annexed hospedería was built.

[3] Annexes to it were two other Colegios Menores: the one on Burgos (1520), which disappeared in the second half of the 17th century, and the one of St. Peter and St. Paul (suppressed in March 1563 by agreement of the students themselves).

It currently occupies a recently constructed building, located next to the Miguel de Unamuno campus.

Its most striking elements are the facade and the imperial staircase inside the palace, where there is also an interesting bust of Miguel de Unamuno, made by Victorio Macho in 1930.