‘Young people of Ireland, I love you,” called out Pope John Paul II to the hundreds of thousands who had gathered in Galway in October 1979. The crowd at Ballybrit racecourse responded effusively, singing and cheering. It was a glorious moment for the man who had made it all happen: Bishop Eamon Casey.

Standing in the rain for hours waiting for the Pope’s helicopter to appear through the clouds, the young people had been entertained by two of the country’s best-known clerics. The ebullient Casey, bishop of Galway, and Fr Michael Cleary, the singing priest, whipped the crowd up into an ecumenical frenzy with jubilant song and prayer.

On that October day, Casey and Cleary were only the support act, but in the early 1990s they would upstage and eclipse the entire Catholic Church in Ireland. The revelation that both had fathered children precipitated a crisis in the church from which it has never fully recovered.

In 1992, after Annie Murphy, an American divorcee, revealed the details of her affair with Casey and the existence of their son, Peter, the bishop resigned from his post and fled Ireland. Although he has returned intermittently, the church seems happier for him to stay away. It is his very ebullience, which proved so invaluable on that wet October day, that it fears.

“I don’t know that he is capable of leading the quiet, retired life,” said one bishop a few years ago. “If he walked into a place, he would be running it in no time. He’s a great organiser. He’s full of ideas.”

Last week Casey, 78, was again thrust into the spotlight. He was forced to leave his post as curate in Staplefield, West Sussex, where he has served since 1998, after an allegation of sexual abuse was made against him.

Severe doubt has been cast on the allegation, which was made by a middle-aged woman who has known Casey for most of her life and has made similar and unproven allegations against others. But when claims of abuse are made against clerics now, certain steps have to be followed. The real question is whether the increasingly frail Casey will ever hold clerical office again.

Born on April 24, 1927, into a family of 10 in Firies, Co Kerry, he was brought up in neighbouring Adare, Co Limerick, where his father was a creamery manager. After attending school at St Munchin’s College, he studied at the Maynooth seminary and was ordained a priest in 1951, along with Cardinal Desmond Connell.

In an interview with Veronica Guerin in 1993, Casey recalled an uneasiness with celibacy that he could trace back to his time in Maynooth and later in England. “Celibacy was unquestionably a factor,” he said. “Two or three times in my seven years at Maynooth it became very much a factor and I had to engage in serious counselling sessions. There were no girls involved at the time.

“It wasn’t that I was looking for female company or a sexual experience. But working outside — pastoral work — disorientated me for a while. I think that celibacy requires community in two senses. Firstly, as a community to serve, to live and to be loved by and, secondly, in the sense of companionship. In London I had neither.”

Casey’s reputation for action was established in the early years of his priesthood. He tackled poverty and homelessness in inner-city parishes in Limerick and later in England. Footage from RTE’s archives shows the young priest in Slough in southeast England working to provide assistance to immigrant Irish families in need. In 1965, he raised money to prevent a young family being evicted from their apartment. Such incidents prompted Casey to set up a loan scheme for Irish immigrants in need of housing. He was also the inspiration behind Shelter, a British organisation that helps the homeless, and he established Trocaire, a Third World charity.

At the age of 42, Casey was appointed bishop of Kerry; seven years later he was transferred to Galway. He used his prominent position to lend support to political and social movements, including taking the side of Dunnes Stores’ staff when they refused to sell fruit from apartheid South Africa.

In 1980, he witnessed the massacre at the funeral of Archbishop Oscar Romero, assassinated by El Salvador’s military regime. He made his outrage known, lobbying the United Nations, the White House and international governments. During Ronald Reagan’s visit to Ireland in 1984, Casey snubbed the US president in protest at America’s supply of military aid to the Salvadorean army. The maverick was becoming increasingly irreverent.

Times Recommends

• The Japanese Prime Minister is doomed: or is he?
• Brighton company 'involved in cyber attack'
• The art of survival: it’s all in the mind