The first work to demonstrate the importance of pawn structure: "Les pions sont l' âme du jeu." Equally famous as a musician in his own lifetime, Francois André Danican Philidor (1726-95) was for over 40 years the leading player in the chess circles of Paris and London. When, in 1745, the cancellation of a musical engagement left him stranded in Rotterdam, he turned to chess as a livelihood, and found many willing opponents among the English army in Holland. He first visited England in 1747 under the patronage of Sir Abraham Janssen, the strongest English player, but returned to Holland in 1748 in order to secure subscribers for a book on chess. "In this he was most successful." The Analyze du Jeu des Échecs was published in London when the author was 23, with a list of 127 subscribers, and 433 copies were sold. There were two reprints in the year of publication. Many other editions followed, and when Philidor eventually revised the work its main features were left unchanged. Philidor's analysis received a mild challenge from the Parisian amateurs, and a major rebuttal by the Modenese masters. But the lucidity, self-assurance and accessibility of his book, which went to unprecedented lengths to explain the moves, succeeded in making it the most enduringly popular of all early chess books. "Philidor belonged essentially to the school of Lopez..... But he was not only the first player to realize and state the principles that lay behind Lopez's analysis, but also the first player to carry those principles to their logical conclusions and to embody them in a system of play ... Everything is subordinated to the effort to conduct a Pawn to Queen ... the formation of a strong centre of Pawns is advocated as the simplest initial step towards the end" (cf Murray pp.861-70).