A controversial law curtailing Indigenous rights in Brazil has come into force, marking a victory for the powerful agribusiness caucus in congress. Critics say this fails to acknowledge that many Indigenous groups had been displaced from their ancestral lands before that date, notably during Brazil’s 1964-1985 military dictatorship, and will invalidate scores of legitimate claims for Indigenous land demarcation. Brazil’s supreme court vindicated such claims when it ruled that the time marker thesis was unconstitutional in a 9-2 vote in September. Activists warn that the law nonetheless represents a clear attack on Indigenous rights and exposes Native Brazilians to the risk of further violence. Indigenous organisations and leftist political parties have said they are preparing to challenge the law in the supreme court.