Michael Griffiths was born in London on December 4 1928, to Hilda and Henry Griffiths.
He attended a prep school in Brighton and then moved north to attend the Ampleforth Preparatory School at Gilling Castle in north Yorkshire and from there moved to Ampleforth School for his secondary education.
In 1946 he won a place at Balliol College, Oxford, where he obtained a first class BSc honours degree in Natural Sciences, majoring in Chemistry. Seven years later he obtained his MA.
On September 24 1950, after completing his studies at Oxford, he joined the Benedictine community at Ampleforth Abbey and was given the religious name Ambrose after the saint who was Bishop of Milan in the fourth century.
He was sent to the Benedictine House of Sant’ Anselmo in Rome where he studied theology and was ordained priest on July 21 1957.
He taught science, RE and woodwork at Ampleforth from 1958 to 1972 and became head of the science department at the school.
From 1963 to 1971 he also taught dogmatic theology to the young monks of the community.
In 1972 he was appointed procurator (bursar) of the abbey and was responsible for the day-to-day running and financial affairs of the abbey.
In 1976 he was elected abbot of the abbey by the community and was in charge of Ampleforth for eight years until he was appointed parish priest of St Mary’s in Leyland, Lancashire. After finishing his term as abbot he was appointed as Titular Abbot of Westminster.
On January 11 1992 Pope John Paul II appointed him as the 11th Bishop of Hexham and Newcastle to succeed Bishop Hugh Lindsay, who had tendered his resignation as bishop of the diocese on the grounds of ill- health. On March 20 1992, he was ordained bishop by Archbishop Derek Worlock of Liverpool in St Mary’s Cathedral, Newcastle upon Tyne.
Bishop Griffiths tendered his resignation at the age of 75. He was succeeded by Bishop Kevin Dunn, who died in 2008. In January 2011 Bishop Griffiths was diagnosed with acute myeloid leukaemia.
Bishop Seamus Cunningham, the current Bishop of Hexham and Newcastle, said: “I visited Bishop Ambrose Griffiths just a few weeks ago. He knew then that he had only a short time left and was dying as he had lived – full of gratitude and hope.
“His gratitude was for those who were caring and praying for him; his hope was in the Lord whom he has served so faithfully. His infectious enthusiasm meant that his ministry as bishop of our diocese was a time of great blessing for us.
“He had a special gift for getting alongside young people and inspiring them to pass on their faith; the formation of the youth ministry team and the foundation of the Youth Village came about thanks to his inspiration. Always approachable and kind to laity and clergy alike we will miss him and pray for him with great thanksgiving.”