The trial on a treasonable felony charge of Nnamdi Kanu, the leader of the Indigenous People of Biafra (IPOB), opens in Federal High Court in Abuja.
The country's 1967-70 Biafra civil war started with a bid for independence by three eastern states, and the dream didn't die with the defeat of the secessionists in 1970. Separatists in the Niger Delta region plan to declare independence from Nigeria on Oct 1, and have ordered northern Nigerians to leave.
Kanu is being tried with three associates, Chidiebere Onwudiwe, Benjamin Madubugwu and David Nwawuisi.
He is accused of conspiring in 2014 and 2015 to broadcast preparations for secession from Nigeria "with a view to constituting same into a Republic of Biafra."
President Muhammadu Buhari, already juggling the Islamist Boko Haram insurgency in the north and militancy in the oil-rich Niger delta, is taking a hard line against independence activism in the once-Biafran nation.
Date written/update: 2017-07-13