Since the 80s, the use of digital corpora has greatly spurred on the study of the history of the Spanish language, especially given that all the evidence for language change over time is derived exclusively from examining old texts. Internet access to Spanish historical digital corpora makes carrying out a detailed search of certain Spanish morphological and syntactic 34features relatively easy and efficient. In this chapter, we will compare and contrast the three most important Spanish historical databases available on the Internet – namely, the two corpora prepared by the Royal Spanish Academy, Corpus Diacrónico del Español (CORDE), Corpus del Nuevo Diccionario Histórico (CDH); and Mark Davies’ Corpus del Español (CE). Included in this review are brief comments about several other interesting but less comprehensive corpora: Biblioteca Digital de Textos del Español Antiguo (BiDTEA), Corpus Hispánico y Americano en la Red: Textos Antiguos (CHARTA), Corpus de Documentos Españoles Anteriores a 1800 (CODEA+ 2015), Corpus Diacrónico del Español del Reino de Granada (1492–1833) (CORDEREGRA), Oralia Diacrónica del Español (ODE), Biblia Medieval, Corpus Léxico de Inventarios (CorLexIn). Accordingly, our intent is to give a useful panorama of the major digital resources available for doing research about the history of the Spanish language.