The symposium will bring together historians of mathematics and astronomy and will analyze the astronomy textbooks published in Portuguese (originals or translations) and in use in Brazil and Portugal in the 18th, 19th and 20th centuries. In this period, astronomy underwent rapid and profound changes. Throughout the 18th century, astronomy, which focused almost exclusively on astrometry and the celestial mechanics of the solar system, evolved into new scientific areas due to the great experimental innovations that were made. The study of electrical and magnetic phenomena and light are research themes that received the attention of many astronomers, and astronomy has opened up to new fields, such as astrophysics. At the same time, with the creation of national technical and scientific education systems, astronomy education was thoroughly reorganised and systematised. New disciplines and textbooks appeared in higher education institutions.