Pope Francis has appointed a marathon-running cleric as the new Bishop of Derry.
Co Antrim churchman Donal McKeown, 63, the current Auxiliary Bishop of Down and Connor, said he felt "energised" by the challenge of his new role.
The post has been vacant since 2011 when Bishop Seamus Hegarty retired due to ill-health.
In the interim period, two diocesan administrators have been in charge of the interests of the parish - initially Monsignor Eamon Martin and, when he left to become Coadjutor Archbishop of Armagh, Father Francis Bradley took on the temporary role.
Addressing parishioners at his presentation at St Eugene's Cathedral in Derry, Bishop McKeown revealed that he was informed of his appointment by the papal nuncio to Ireland, Archbishop Charles Brown, last week.
"We all know that things in life can change very quickly," he said.
"Man proposes but God disposes. It is only six days since my work in Belfast was interrupted by an invitation to go to Dublin to meet the Apostolic Nuncio that afternoon. Archbishop Brown's words still ring in my ears - "The Holy Father has chosen you to be Bishop of Derry". They sound so disarmingly simple.
"However, as we prepared for this announcement this morning in the beautiful Saint Eugene's Cathedral, I began to realise just what an enormous task is involved."
The cleric acknowledged that many in the city have suffered hard times, with the violent legacy of the Troubles, historic institutional child abuse scandals and recent major job losses all having impacted on the area.
"But Pope Francis has given us all huge encouragement to be people of faith in the realities of our time and environment," he said.
Bishop McKeown, who noted that he had spent all of his 37 years in the priesthood to date in the diocese of Down and Connor, primarily in Belfast, said he was happy to become part of a "team of the pilgrim people in the diocese of Derry".
"Leadership is important - but its only task is to ensure that people on the ground can be helped to blossom, develop and work together in the service of the common good," he said.
"Leadership is a service, not an honour."
"I believe that this is an exciting time to witness to, and speak the Gospel, into the Church and into civic life. As a society, we have to discern what sort of communities we want to build. We have wonderful new opportunities to travel, to learn and to exploit modern technology. But we all need to engage to seek agreement on what we consider true, or good or beautiful. If there are no shared values, no shared vision for what sort of future we want to build for our children, then it is difficult for a society to hold together and grow."
He insisted that the churches in Ireland had a role to play as "critical friends" of the political structures.
He added: " I look forward to working with people of faith and people of doubt within this wonderful and historic diocese, so that together we can generate hope for our young people. I feel energised by this challenge."
Father McKeown was appointed Auxiliary Bishop of Down and Connor in 2001 after a long teaching career in first St Patrick's College and then St Malachy's College in Belfast.
The eldest of four children, the Randalstown-born cleric is an honours graduate in German and Italian from Queen's University Belfast. He also spent five years at the Gregorian Pontifical University in Rome studying philosophy and theology.
The keen Gaelic footballer and fluent Irish speaker was ordained as a priest in Randalstown in 1977.
As a member of the Irish Catholic Bishops' Conference, his recent responsibilities have included the promotion of Catholic education, youth ministry, university chaplaincies and the promotion of vocations to the priesthood and religious life.
His stated interests include the interface between faith and the empirical sciences and work with Catholic schools in Norway, Denmark, Lithuania, Poland and Germany.
He is also well versed in dealing with and working for media organisations.
In the early 1970s he was Belfast correspondent for the German Catholic news agency, KNA.
While in Rome he also did some work with Vatican Radio and has also worked on reports in the Irish language for Irish broadcaster RTE.
He continues to be a regular contributor to radio and television across Ireland, as well as having opinion articles published in newspapers and periodicals.
Describing himself as a life-long sports enthusiast, Bishop McKeown has completed two Belfast marathons and continues to take part in a relay team for the annual marathon in the city.
Catholic Primate of Ireland Cardinal Sean Brady congratulated Bishop McKeown on his appointment.
"I am confident that Bishop McKeown has the gifts and qualities needed to lead the Diocese of Derry," he said.
"As well as being an excellent communicator, his experience in Catholic education, parish ministry and diocesan administration have shown his wonderful ability to lead people by word and example. All of this has prepared him well for this special day."
Cardinal Brady said the cleric was very popular with all age groups, noting that he had led many pilgrimages to World Youth Day events, the most recent one to Rio de Janeiro in Brazil last July.
He added: "I know for certain that Bishop McKeown will have many prayers from the people of the Diocese of Down and Connor he has served so generously.
"I too wish him prayerful good wishes as he takes up his new episcopal ministry in Derry."
Bishop of Down and Connor Noel Treanor paid tribute to his departing colleague.
"He is a man of boundless energy and vibrant Christian hope," he said.
"He has worked with courage and dedication to develop community relations and to further ecumenical understanding and dialogue. He has worked steadfastly to build solid foundations for peace with justice and to promote reconciliation and respect as the foundation stones of community, civic and public life."
Good wishes also came from senior Protestant churchmen.
Bishop Ken Good, from the Church of Ireland diocese of Derry and Raphoe, welcomed the appointment.
"I have known Bishop Donal for many years and look forward to a warm working relationship with him," he said.
"We were both teachers, have run marathons and have been involved in many fruitful discussions about the future of our community.
"Bishop McKeown has a commitment to building peace in our community and he will receive a warm welcome in our city. We offer our prayers and good wishes for his new ministry in Derry diocese".
Presbyterian Moderator Dr Rob Craig, who is also the minister of Kilfennan Presbyterian Church in Londonderry, said he looked forward to working with Bishop McKeown.
"I know he will be warmly welcomed, just as I was 20 years ago, and will find a people keen to live together side by side respecting one another, strengthened by their diversity and united in their love for the north west," he said.
"While I don't know Bishop McKeown personally, he is held in high regard by my Presbyterian colleagues who minister with him in Belfast and who serve alongside him in the area of state education.
"I welcome him to the city and assure him of our prayers and good wishes for the days ahead."