Giovanni de Galliano Pieroni

Giovanni de Galliano Pieroni (1586–1654) – military engineer specializing in erecting fortifications (authored Trattato delle fortificazioni moderne), architect, mathematician and astronomer who gained particular fame in his day as also as author of horoscopes. Just the same he was a practicing astronomer and a contemporary and a friend of Johannes Kepler (1571-1630) while both spent time in Prague. Earlier he became friendly with the astronomer, mathematician and physicist Galileo Galilei (1564-1642) – like Pieroni, Galileo also wrote on constructing fortifications, and the two shared interest in mathematics and astronomy.

Biography
Pieroni was born in Florence. His childhood and education was privileged, in that his father Alessandro (1550-1607) was an architect at the court of the Medici. After studying law, in 1608 he was awarded a doctorate in law in Pisa. He studied under Bernardo Buontalenti (1531-1608). During that time he befriended Galileo, who served then the Tuscan Grand Duke, Cosimo II di Medici. The two corresponded for many years, even after Pieroni left Florence.

He spent a lot of time working for general Albrecht of Wallenstein (1583–1634), in Vienna and Prague, fixing up fortifications of castles and in that vein, of palace and park grounds, particularly the Wallenstein Palace, collaborating with great baroque Italian artists and architects. His young assistant in both cities was Baccio del Bianco, who memorably described Pieroni as an "astrological architect".