"I have been privileged and truly blessed to have served as a bishop for 30 years and as archbishop of Toronto for 16 years," he said in a statement to the congregation before giving the homily at the cathedral.

"In this time, I have come across many wonderful and faithful Catholics who have given of themselves for the love of the church. . .. On a day like today, I wish to give thanks to those around me, who have faithfully served the diocese and supported me in my ministry."

Ambrozic will hand over the keys to the archdiocese to Archbishop Thomas Collins of Edmonton, whose transfer to Toronto was announced Dec. 16 by Pope Benedict XVI. Collins, 59, will be installed early in the new year. The cardinal was to meet with Collins Dec. 19 to discuss the handover.

In the meantime, the archbishop's seat is considered vacant, though Ambrozic will continue to be apostolic administrator with responsibility for the day-to-day duties of the archdiocese.

The cardinal said he had not yet begun to think about what he will do in his retirement. Ambrozic handed his resignation to the Pope, as required by church law, when he turned 75 in January 2005, but Pope John Paul II asked him to stay on for a couple of years.

"People have asked me what I will do, I just want to get used to being retired," he said.

The cardinal expressed his gratitude to everyone from his auxiliary bishops, to priests, permanent deacons and all the lay people "who continue to be the hands of Christ among us."

"Finally, I give thanks to God for entrusting me, your humble servant, as archbishop of Toronto. The greatest reward one can experience in one's life is to serve Jesus," he said. "For this, I will be eternally grateful."

With his retirement, the cardinal brings to a close a 30-year career as bishop. In March 1976, Pope Paul VI called and then Fr. Ambrozic, a popular Scripture professor at St. Augustine's Seminary in Toronto, became Bishop Ambrozic, auxiliary to Archbishop Philip Pocock. His job was to oversee pastoral care of the archdiocese's central region and the ethnic communities.

Though it was an unexpected honour, he took to his new job dutifully and energetically. In 1984-85, he made pastoral visits to all 43 Catholic high schools in the archdiocese to strengthen and support religious education. He was also a member of the Christian Education Commission of the Canadian Conference of Catholic Bishops and helped revise the Canadian catechism.

On May 22, 1986, he was appointed coadjutor archbishop, meaning he had been selected to fill the shoes of Cardinal Gerald Emmett Carter on his retirement. On March 17, 1990, he was made archbishop. Then, in January 1998, Pope John Paul announced that Ambrozic would become the third cardinal in Toronto's history.

In 2002, Pope John Paul paid the cardinal a visit in Toronto, along with hundreds of thousands of young people who attended the World Youth Day in July of that year. It was a festival of faith that transformed Canada's most secular city for a week.

During Ambrozic's time, the face of the church in Toronto has changed dramatically. Fuelled by a flood of immigrants from countries around the world, it has grown from a Catholic population of 1.1 million in 1986, when he was coadjutor archbishop, to more than 1.6 million today. To respond to the rising demand for spiritual nourishment and religious services, he has overseen the construction of 25 new churches, most in the rapidly expanding suburbs around the city.

"In a sense, in his person he represents the fact that the church of Toronto has evolved a huge distance from the church as it was at the beginning of the 20th century when it was still largely dominated by Irish Catholics," said Dr. Richard Alway, president of the University of St. Michael's College and a long-time personal friend of the cardinal.

Alway was referring to Ambrozic's immigrant roots. The cardinal came to Canada as a teenager with his family in the 1950s, leaving a displaced persons camp in Austria that had been his home for several years after the family fled war and strife in his native Slovenia at the end of the Second World War. The refugee experience, and his gratitude at finding a welcoming home in Canada, have coloured his entire outlook toward the country and his flock.

"Newer Canadians can identify with him," said Alway. "They had a story, he had a story. It was an experience they shared in common."

During his time as bishop and archbishop, lay movements and groups, many ethnically based, flourished and some of the ethnic (often called national) parishes became some of the most lively parishes in the diocese.

As a former professor, Ambrozic also believed it was important to strengthen seminary education for budding priests. Auxiliary Bishop John Boissonneau, who had been rector of St. Augustine's for nine years during Ambrozic's time, said the cardinal had always been extremely supportive.

"He was a professor at St. Augustine's and one of the pioneers at the Toronto School of Theology (an ecumenical school that brings together the theological resources of the Church-based colleges associated with the University of Toronto)," Boissonneau said.

"That's very important because he understands the environment of a strong Catholic presence in an ecumenical setting."

Through his years, Ambrozic supported sending away some of Toronto's most talented young diocesan priests for graduate studies in Rome so that the seminary would have a highly qualified teaching faculty.

"It's very important to him to have diocesan priests prepared with doctorates in theology and the other sacred sciences," Boissonneau said.

Dr. Moira McQueen, director of the Canadian Catholic Bioethics Institute, said the cardinal had been instrumental in establishing the think tank in 2001 to help the church in Canada research some of the most controversial moral issues facing the human race such as cloning, new reproductive technologies, stem-cell research, palliative care, euthanasia and end-of-life treatment.

Based at St. Michael's College, the CCBI promotes research in these issues and organizes meetings of academics and others to help disseminate a Catholic understanding of them.

"I've really found him extremely important both to the institute and to me personally," said McQueen, who also teaches moral theology at St. Michael's College.

"As a theologian, I've been really impressed by his prudential statements over the years on moral issues."

Prominent Catholic businessman Frank Morneau has worked closely with the cardinal on various church projects in the archdiocese over many years. In the early 1990s, he was asked by the cardinal to help renew life at the Newman Centre chaplaincy at the University of Toronto, which was suffering financially and from a lack of student involvement. Morneau has also been active on governing boards at St. Michael's College and St. Augustine's; the cardinal serves as chancellor to both institutions.

"From a lay perspective, he's chosen his advisors and leaders with care and has always taken their counsel to heart," Morneau said.

The cardinal, Morneau added, is clearly a man of deep religious conviction. He is also a man who is willing to show leadership despite the personal cost.

Morneau cited Ambrozic's ability to gather support from other Catholic bishops in Canada to help fund the CCBI, to which the archdiocese is the largest financial contributor.

"We desperately needed that leadership," Morneau said. "We need research on these issues and we need a collective voice and we need a way to convey that message," all of which the CCBI was founded to provide.

Morneau said the cardinal's positions have not always been popular but he has remained true to his convictions and served to the best of his abilities even in recent years when his health has begun to fade.

"He's literally given up his life for others," he said.