Italian violinists and composers. Both probably students of Arcangelo Corelli, they were employed in Rome by Cardinal Ottoboni and Prince Francesco Maria Ruspoli, where they met Handel during his years in Italy. In 1715 they were brought to London by Lord Burlington together with the cellist and composer Filippo Amadel, known as Pippo dal violoncello, where Pietro beame leader of the orchestra for the Royal Academy. Handel returned to London in 1719 or 1720 and the brothers were part of the concertino when he presented Radamisto, and remained such for some 20 years, something attested to by mentions in his manuscipts.

Pietro is considered the inventor of the Violetta marina . This instrument, a small violain its delicacy is not dissimilar, had the range of an ordinary viola. In the aria "Giˆ l'ebro million ciglio" in the opera Orlando Handel composed a part for this instrument for both brothers Castrucci.

Pietro also published several collections of sonatas and concertos and became the more famous of the brothers. Prospero published only one collection, of six sonatas, in 1739.