Fr Fernando Cardenal was a Jesuit priest who joined the left-wing Sandinista uprising in Nicaragua after it toppled what many say was the dictatorship of Anastasio Somoza in 1979.
Under the Sandinista administration of Daniel Ortega, Fr Cardenal was widely praised for leading a reading campaign that brought illiteracy in Nicaraguan adults down to 13%.
He then served as Education Minister from 1984 to 1990.
The priest was a prominent supporter of Liberation Theology, a branch of Christian thought which encourages the reading and application of Scripture through the eyes of the poor, and argues one of the central aims of a Christian should be to eliminate the systems and practices which allow poverty and slavery to exist.
Critics of Liberation Theology say it mixed Christianity with Marxism, a political ideology.
Different pontiffs have had different opinions on Liberation Theology.
When Fr Cardenal joined Sandinista in 1979, the Vatican under the auspices of Pope John Paul II ordered him to to leave.
On refusal he was suspended from the Jesuit order, however in a rare move the Vatican reinstated him in 1996.
After his time as Education Minister he continued teaching in schools in poor areas of Nicaragua.