Mendelssohn worked out his publishing career strategically. His first opus numbers established his place in various genres and styles. In his maturity, regular publication of roughly one major work per year supported his reputation as a composer of serious music. Modestly scored pieces accommodated the domestic music market, as did larger works in two- or four-hand piano arrangements. Early nineteenth-century laws established copyright within countries, but no international agreements prevented pirated editions beyond borders. Negotiations with publishers therefore occupied much of Mendelssohn’s time and energy. Mendelssohn undertook two substantial editions of music by his eighteenth-century forebears, Handel’s Israel in Egypt, and Bach’s organ music. Insisting on a rigorous editorial policy, he anticipated now-standard musicological principles. Fanny Hensel began publishing late, the small number of her publications reflecting social and familial constraints. Seven opus numbers appeared during her lifetime, all within her last year and all addressing the bourgeois, domestic audience. Four posthumous works resulted from her family’s project to honour her and promulgate her music.