This article explores a slice of the careers of two ‘rival’ coloratura singers – the Swedish soprano Christine Nilsson and the French soprano Caroline Miolan Carvalho – during the period 1867 to 1870, and considers the internationalisation of singing careers, women's choices and negotiation of their career paths, and fortunes made and lost. With both singers employed at the Paris Opéra from November 1868 onwards as Gounod's Faust went into rehearsal, the focus falls on the ‘Battle of the Marguerites’ in the Parisian press in spring 1869, which raised heated questions of dramatic and vocal interpretation and style, often linked to cultural stereotypes, as well as artistic legitimacy and stature. Through examination of previously overlooked archival financial and legal records, this article also reveals for the first time that Miolan Carvalho was indentured to the director of the Opéra Emile Perrin during this period.