There is a whole group of manuscripts know as Testerian; the name applies to pictorial catechisms produced in New Spain by Franciscans and Dominicans to help in the conversion of the natives. Around 25 of those works are extant. One of the oldest is the Catechism of Fray Pedro de Gante, though to have been written between 1525 and 1528.
The drawings appear to be very old; they are not only illustrations of the text, nor simple aide-mémoires, for they also incorporate characters in a script which was translated into nahuatl, the language of the Aztecs. This type of writing is a direct descendant of the pictographs used by the indigenous natives, and which includes a number of elements, not only icons and other symbols but also phonetic characters. On page 3 there is an inscription in violet ink which says "Archivo Historico Nacional". The book has been in the National Library since 20 January 1867.
We have 1 facsimile edition of the manuscript "Cathechism of Fray Pedro de Gante": El catecismo de Fray Pedro de Gante facsimile edition, published by Testimonio Compañía Editorial, 1992