The leader of the Nigerian secessionist state of Biafra, where haunting images of underfed children caught in a civil war shocked the world, has died at age 78, officials said Saturday.

Chukwuemeka Odumegwu Ojukwu died in the United Kingdom, according to Nigerian President Goodluck Jonathan. A government spokesman said Ojukwu died from effects of a stroke.

The 1967-1970 Biafra civil war occurred after Yakubu Gowon took power in a coup d’etat in 1966.

Ojukwu, than a military governor, and his followers rejected plans for reconciliation following violence against the Igbo people in the north and broke away.

“He cited as the principal cause for this action the Nigerian government’s inability to protect the lives of easterners and suggested its culpability in genocide, depicting secession as a measure taken reluctantly after all efforts to safeguard the Igbo people in other regions had failed,” according to globalsecurity.org, a public policy organization.

Estimates of the number of dead from hostilities, disease, and starvation during the 30-month civil war are estimated at between 1 million and 3 million, according to globalsecurity.org.

The war ended in January 1970, when Ojukwu fled and Biafra was reabsorbed by Nigeria.

Multi-ethnic Nigeria has been plagued by religious and communal violence since independence from Britain in 1960.

“Chief Ojukwu¹s immense love for his people, justice, equity and fairness which forced him into the leading role he played in the Nigerian civil war, as well as his commitment to reconciliation and the full reintegration of his people into a united and progressive Nigeria in the aftermath of the war, will ensure that he is remembered forever as one of the great personalities of his time who stood out easily as a brave, courageous, fearless, erudite and charismatic leader,” Jonathan said in a statement.