The name refers to the fact that his was the private library of Marcelino Menéndez Pelayo, a renowned Spanish intellectual from the late 19th and early 20th century. His collection caters for the concerns and research of an expert in Humanities, Bibliography, and Historical and Literary Studies. In his will, he donated the collection, together with the building and garden where it was housed, to the city of Santander. He also stipulated that no further items were to be added to the collection after his death (which occurred in 1912).