Europe as an active boundary concept dates mainly to the twentieth century

Evidence

While “Europe” is an old concept it did not gain currency until the seventeenth century and, by and large, only became an active boundary as such in the course of the nineteenth century and particularly from the beginning of the twentieth century. — David Theo Goldberg, John Solomos, A Companion to Racial and Ethnic Studies, 175

Categorization

• XREF: Historically contingents Europe suggests parallels with the vault’s claims about how racial categories acquire fixed boundaries only at specific historical moments. — connects to: Exclusive territorial national jurisdictions are a recent twentieth-century invention — Charles Tilly, Regimes and Repertoires, 191
• corroborated: 2 independent passages support this claim — David Theo Goldberg, John Solomos, A Companion to Racial and Ethnic Studies, 175