An ancestral form of Basque known as Aquitanian appears in Roman inscriptions in Aquitaine, in the southwest of France. The inscriptions consist of the names of people and gods plus a few other words and were inscribed during the 1st and 2nd centuries AD.

Basque first appeared in writing in Latin religious texts, the Glosas Emilianenses, dating from the 11th century. The first published book in Basque was a collection of poems entitled Linguae Vasconum Primitiae, published by Bernard Detchepare in 1545.

For centuries there was no standard orthography, and Basque was written with Romance spelling conventions supplemented by various additional devices to represent sounds not present in Romance languages. During the early years of the 20th century, a bizarre and impractical orthography employing a blizzard of pointless diacritics was widely used; this largely disappeared after the Spanish Civil War. In 1964 the Royal Basque Language Academy (Euskaltzaindia) promulgated a new standard orthography; this met some resistance at first but is now almost universally used.