Complex sentence: Giulio's drawings have always been treasured by collectors, and the contemporary engravings after his drawings and paintings by Marcantonio Raimondi and others helped spread 16th century Italian style throughout Europe.
Split into simpler sentences: Giulio's drawings have always been treasured by collectors. The contemporary engravings after his drawings, and after paintings by Marcantonio Raimondi and others, helped spread 16th century Italian style throughout Europe.