 figures seemed to possess. Berenson’s categorizing tendency toward art history grew with the publication of Central Italian Painters (1897), the third of his Italian schools-of-art books. Here artists were divided into rankings such as "decorators" or "illustrators," or when these categories failed, the artists were organized by those employing spatial techniques whose results could, again according to Berenson, elicit specific "ideated" sensations from the viewer. Berenson's books quickly found a wide readership, providing him a steady, if modest, source of income. They rapidly became the texts for the nascent art history courses being developed in American universities. In 1900, Berenson bought a villa in the Tuscan hills of Settignano, outside Florence. Villa I Tatti subsequently would be forever associated with Berenson. The same year Mary Costelloe's husband died and she married Berenson. The two transformed the eighteenth-century house and gardens into a personal center for renaissance study. Berenson's library was famous and his guests numerous. He remained there, except for periodic travel, the rest of his life. At the villa he completed the first study of a school of drawing by an art historian--Berenson's only catalog--Drawings of the Florentine Painters (1903). A work of lasting importance, Drawings was an illustrated catalog of known Florentine drawings and a separate text describing and analyzing each artist using Berenson's critical method and assumptions of personality. Berenson collected his articles into three series each called, The Study and Criticism of Italian Art, a compilation of early articles. The Berensons traveled to the United States in 1903 meeting the important American collectors, Henry Walters (1848-1931) in Baltimore, and Peter Widener (1834/6-1915) and John Graver Johnson (1841-1917) in Philadelphia. Berenson's relationship between dealer and advisor became ever more ambiguous during this time. Unbeknownst to the Metropolitan Museum of Art, he received over $3000 in a personal commission for a sale of an El Greco he recommended to them in 1905; occasionally he assisted in the smuggling of works to America. In 1906 Berenson hired Geoffrey Scott, a young classics student from Oxford to be his secretary/librarian; his wife, Mary, fell deeply in love with him. In retaliation to Mary for this affair, he started his own tryst with the librarian hired by J. Pierpont Morgan (1837-1913) for his collection, Belle da Costa Greene (1883-1950). North Italian Painters of the Renaissance, the final book of the quartet on Italian painters, appeared in 1907, in many ways his least successful book because these painters resisted Berenson's stylistic analysis. Berenson, who had previously been taking percentages from dealers for sales to those he advised, such as Isabella Stewart Gardner and others, first accepted a confidential retainer fee from Agnew Galleries. That same year, 1907, after introducing Mrs Gardner to the aggressive and unscrupulous art dealer Joseph Duveen (1869-1939), he sealed a secret deal with Duveen. Though Berenson had advised Duveen since 1906, the new agreement cut him in an unconventional 25 percent of the total Duveen sale. Duveen used Berenson's authority to sell pictures to the wealthiest collectors in the United States (and former Berenson confidents) Morgan and Joseph E. Widener (1871-1943). Berenson published a volume on Stefano di Giovanni Sassetta in 1909. He wrote the catalog of the Widener's collections in 1913, which he himself helped assembled, and again for Johnson in 1916. He was one of the original six contributors to the first issue of Art in America in 1913, which Duveen bankrolled in order to educate American collectors. Berenson published the first and second of his four major works, Venetian Painting in America, and the third series of The Study and Criticism of Italian Art in 1916. His war duty for World War I consisted of translating and negotiating in Italy, duties recommended by his friend, the author and art writer Edith Wharton. The third book of his qua