VATICAN CITY — Cardinal Achille Silvestrini, former prefect of the Congregation for Eastern Churches and a long-time Vatican diplomat, died at his home in the Vatican Aug. 29 at the age of 95.

Cardinal Silvestrini served in the diplomatic corps of the Holy See in Rome and abroad for nearly 35 years, before being named prefect of the Supreme Tribunal of the Apostolic Signatura and later prefect of the Congregation for Eastern Churches, where he served until his retirement in 2000.

Cardinal Silvestrini was born in Brisighella, Italy in 1923. Ordained a priest in 1946, at age 30 he entered the diplomatic service in the Vatican’s Section for Extraordinary Ecclesiastical Affairs of the Secretariat of State, dealing with the problems of Vietnam, China, Indonesia, and South-East Asia. 

He was a collaborator to the secretaries of state Cardinals Domenico Tardini and Amleto G. Cicogani, and later was put in charge of the International Organizations Sector.

During his diplomatic career, the cardinal played an important role in the negotiations between Italian authorities and the Holy See on the agreement revising the Lateran Treaty in1984. 

Prior to that, in the 1970s, Cardinal Silvestrini was a key representative for the Holy See on the issue of international nuclear arms limitation. As a participant in the Conference on Security and Cooperation in Europe he travelled to sessions in Helsinki and Geneva.

In 1971, he accompanied Cardinal Agostino Casaroli to Moscow in order to deposit the document of adhesion of the Holy See to the Treaty of non-proliferation of nuclear arms.

The cardinal also headed the delegations of the Holy See to the Conference of the United Nations on the pacific use of nuclear energy and the conference putting into effect the treaty on the non-proliferation of nuclear arms.

In July 1973, he was named under-secretary of the Council for Public Affairs of the Church (which in 1988 became part of the Secretariat of State in the Section for Relations with States). Six years later he was promoted to secretary of the same council and the same month was ordained a bishop.

Pope St. John Paul II promoted him to archbishop in May, 1979, before further elevating him to cardinal in June 1988, at the time of his appointment as head of the Apostolic Signatura - the Vatican’s supreme court.

More recently, Cardinal Silvestrini was named as a member of the so-called “St. Gallen Group” of about a dozen cardinals who are said to have met to consider and promote candidates ahead of the 2005 and 2013 conclaves.

Cardinal Silvestrini did not vote in the conclaves which elected Pope Benedict XVI and Pope Francis, as he had passed the canonical age of participation when he turned 80, but was widely recognized as a leader among several cardinals in favor of electing a theological reformer. 

The St. Gallen Group, which met primarily between 1995 and 2006, was named after the host of the discussions, the Bishop of St. Gallen, Switzerland, Ivo Furer. With Cardinal Silvestrini’s death, eight of the 10 cardinals said to have been in the group are now deceased.

In his priestly ministry, Cardinal Silvestrini was connected to Villa Nazareth, an institution for helping youth and since 1969 had animated a community consisting of a group of university graduates, professionals, and supporters.