acquisition of The Madonna of the Rosary (Kunsthistorisches Museum, Vienna) for the St. Paul's Church in Antwerp. During this first stay in Rome, Rubens completed his first altarpiece commission, St. Helena with the True Cross for the Roman church of Santa Croce in Gerusalemme. Rubens travelled to Spain on a diplomatic mission in 1603, delivering gifts from the Gonzagas to the court of Philip III. While there, he studied the extensive collections of Raphael and Titian that had been collected by Philip II. He also painted an equestrian portrait of the Duke of Lerma during his stay (Prado, Madrid) that demonstrates the influence of works like Titian's Charles V at Mühlberg (1548; Prado, Madrid). This journey marked the first of many during his career that combined art and diplomacy. He returned to Italy in 1604, where he remained for the next four years, first in Mantua and then in Genoa and Rome. In Genoa, Rubens painted numerous portraits, such as the Marchesa Brigida Spinola-Doria (National Gallery of Art, Washington, D.C.), and the portrait of Maria di Antonio Serra Pallavicini, in a style that influenced later paintings by Anthony van Dyck, Joshua Reynolds and Thomas Gainsborough. He illustrated books, which was published in 1622 as Palazzi di Genova. From 1606 to 1608, he was mostly in Rome when he received, with the assistance of Cardinal Jacopo Serra (the brother of Maria Pallavicini), his most important commission to date for the High Altar of the city's most fashionable new church, Santa Maria in Vallicella also known as the Chiesa Nuova. The subject was to be St. Gregory the Great and important local saints adoring an icon of the Virgin and Child. The first version, a single canvas (now at the Musée des Beaux-Arts, Grenoble), was immediately replaced by a second version on three slate panels that permits the actual miraculous holy image of the "Santa Maria in Vallicella" to be revealed on important feast days by a removable copper cover, also painted by the artist. Rubens's experiences in Italy continued to influence his work. He continued to write many of his letters and correspondences in Italian, signed his name as "Pietro Paolo Rubens", and spoke longingly of returning to the peninsula—a hope that never materialized. Antwerp (1609–1621) Upon hearing of his mother's illness in 1608, Rubens planned his departure from Italy for Antwerp. However, she died before he arrived home. His return