We examine the making of a gay male world and of modern forms of male homosexuality in late nineteenth-century France,and more specifically in Paris during the Belle Époque,a paradigm of urban modernity no less than London or New York. Although gay people,homosexual practices,and even “homosexual” identities may have existed before the modern period, the influence of medical discourse and a congeries of cultural, economic, political, and social factors in the late nineteenth-century facilitated the emergence of modern male homosexualities, along with a huge and specifically gay world, concentrated in some parts of the Capital.In addition,the Belle Époque is a period of transition between the gender system (in which only “passive” males were considered homosexual) and the system of sexual orientation (in which both, or many, partners are regarded as homosexual simply by virtue of sexual contact) – a system that gradually took over during the twenties and thirties,and became even stronger during the post-WWII period.