Antonio del Rincón was a Jesuit priest and grammarian, who wrote one of the earliest grammars of the Nahuatl

Nahuatl

Nahuatl is thought to mean "a good, clear sound" This language name has several spellings, among them náhuatl , Naoatl, Nauatl, Nahuatl, Nawatl. In a back formation from the name of the language, the ethnic group of Nahuatl speakers are called Nahua...

 language (known generally as the Arte mexicana, MS.

Manuscript

A manuscript or handwrite is written information that has been manually created by someone or some people, such as a hand-written letter, as opposed to being printed or reproduced some other way...

 published in 1595). A mestizo

Mestizo

Mestizo is a term traditionally used in Latin America, Philippines and Spain for people of mixed European and Native American heritage or descent...

 native of Texcoco from the early decades of the Viceroyalty of New Spain and descendant of the tlatoque

Tlatoani

Tlatoani is the Nahuatl term for the ruler of an altepetl, a pre-Hispanic state. The word literally means "speaker", but may be translated into English as "king". A is a female ruler, or queen regnant....

(ruling nobility of Texcoco), del Rincón knew the language of the indigenous Nahua peoples intimately. His grammar ranks alongside those of Andrés de Olmos

Andrés de Olmos

Andrés de Olmos , Franciscan priest and extraordinary grammarian and ethno-historian of Mexico's Indians, was born in Oña, Burgos, Spain, and died in Tampico in New Spain...

 and Alonso de Molina

Alonso de Molina

Alonso de Molina was a Franciscan priest and grammarian, who wrote a well-known dictionary of the Nahuatl language published in 1571....

as an influential primary source for the language as spoken in the post-conquest period.