Which religious order adopted the Decree de genere in 1593?

The Jesuits adopted the Decree de genere in 1593.

The decree applied the Spanish idea of limpieza de sangre to admission to the Society of Jesus. It treated Jewish or Muslim ancestry as an impediment to joining, extending a system of hereditary exclusion beyond a person’s own beliefs or conduct. The policy reflected intense anti-converso pressures in late-sixteenth-century Catholic Europe.

This development is especially notable because some early Jesuits, including people associated with the founding generation, had converso backgrounds. Ignatius of Loyola himself is often discussed in connection with a more inclusive attitude toward people of Jewish ancestry, but the Society’s internal politics moved toward restriction after his death.

The rule did not remain unchanged forever. Its scope and enforcement evolved, and later Jesuit legislation modified the restrictions. The Society’s 29th General Congregation in 1946 formally dropped the ancestry requirement, making 1593 a key date in the history of institutionalized blood-purity rules.