It is evident of the facility with which he acquired the rapid execution of a scene-painter that he was selected to collaborate with Antonio da Sangallo the Younger, Battista Franco and Francesco de' Rossi (Il Salviati) on the redecoration of the Porta San Sebastiano at Rome as a triumphal arch (5 April 1536) in honour of Charles V. Giorgio Vasari, who saw the battle-pieces which Heemskerk then produced, said they were well composed and boldly executed. While in Rome where he made numerous drawings of classical sculpture and architecture, many of which survive in two sketchbooks now in the Kupferstichkabinett Berlin. He was to use them as source material throughout the rest of his career. Among these are the Capitoline Brutus, van Heemskerck being the first known artist to make a sketch of this now famous bust. Later career On his return to the Netherlands in 1536, he settled back at Haarlem, where he became president of the Haarlem Guild of Saint Luke (in 1540), married twice (his first wife and child died during childbirth), and secured a large and lucrative practice. The alteration in his style, brought about by his experience of Italy was not universally admired. According to van Mander, "in the opinion of some of the best judges he had not improved it, except in one particular, that his outline was more graceful than before". He painted large altarpieces for his friend, the art maecenas and later catholic martyr of the Protestant Reformation, (also known as Musius). Muys had returned from a period in France to the Netherlands in 1538 and became prior of the St. Agatha cloister in Delft (later became the Prinsenhof). This lucrative and high-profile work in Delft earned Heemskerck a commission for an altarpiece in the Nieuwe Kerk (Delft) for their Guild of St. Luke. In 1553 he became curate of the Sint-Bavokerk, where he served for 22 years (until the Protestant reformation). In 1572 he left Haarlem for Amsterdam, to avoid the siege of Haarlem which the Spaniards laid to the place. Engravings He was one of the first Netherlandish artists to make drawings specifically for reproduction by commercial printmakers. He employed a technique incorporating cross-hatching and stippling, intended to aid the engraver. Wonders of the World Heemskerck produced designs for a set of engravings, showing eight, rather than the usual seven wonders of the ancient world. His addition to the conventional