He was the youngest son of
Bernardo Castello, who died when Valerio was six years old. Valerio and his brothers were attached to the noble family of Torquato. While it had been the original intention for him to study a literary profession, he showed an affinity for drawing. This was noted by his patrons, who arranged his apprenticeship with
Domenico Fiasella. Later, he studied with Giovanni Andrea de’ Ferrari. To seek new inspiration, he travelled to Milan and then to Parma, probably between 1640 and 1645. In Milan, he admired the work of Camillo Proccacini. From there, he traveled to
Parma. For the house of Francesco Maria Balbi, he collaborated with the
quadraturista from Bologna,
Andrea Sghizzi to fresco the palace. In his works, he is regarded by his admirers as combining the fire of
Tintoretto with the general style of
Paolo Veronese. Castello influenced the work of young
Domenico Piola. He also admired the work of
Anthony van Dyck, who had spent a long time in Genoa and whose paintings could be seen all over the city. Among his pupils were
Bartolomeo Biscaino,
Giovanni Paolo Cervetto, and Stefano Magnasco (the father of
Alessandro). ==References==