Baltimore Archbishop Edwin F. O’Brien has been chosen to head a Catholic order of knights based in Rome, the Vatican announced Monday, an appointment that is likely to lead to his elevation to cardinal. The move will also make O’Brien the first of Baltimore’s archbishops not to finish his career there.

O’Brien, the spiritual leader of the Baltimore area’s half-million Catholics, will continue to serve as apostolic administrator of the archdiocese until a successor is named, an appointment that could take 18 months.

He will have many of the same duties as archbishop but will be limited in his decision-making authority. During the transition, O’Brien said, he will split his time between Baltimore and Rome, mixing in travel to the area of historical Palestine.

Pope Benedict XVI named O’Brien grand master of the Equestrian Order of the Holy Sepulchre of Jerusalem, a 1,000-year-old group charged with supporting the Christian community and sacred sites of the Holy Land.

“It has been a singular privilege to serve as Archbishop of Baltimore,” O’Brien wrote to the pontiff in a letter he read at a news conference Monday. “It is with a heavy heart that I will be departing the Premier See of the United States, but I do so out of complete obedience to Your Holiness.”

O’Brien, 72, who has served as archbishop since October 2007, said that “news of this appointment came as a shock to me and I am still adjusting to the reality that effective today, I am no longer the archbishop of Baltimore.”

He said he accepted the new position Aug. 18, a day after a cardinal called during his visit to Rome to say Pope Benedict was making the appointment.

O’Brien will succeed Cardinal John Patrick Foley, who resigned in February because of poor health. The position of grand master of the order has been reserved for a cardinal by papal decree since 1949, and O’Brien is expected to be given that title.

Asked to reflect on the “highs and lows” of his nearly four-year experience in Baltimore, O’Brien mentioned the restructuring of the archdiocesan school system that was announced last year a “high point” but acknowledged the turmoil of closing 13 of 64 schools and consolidating some others.

“I know the trauma it caused,” O’Brien said. “I don’t regret doing it, but I regret having to do it.”

O’Brien emphasized when the reorganization was announced that the archdiocese had no choice but to make sweeping changes to save the school system in the face of falling enrollment, rising costs and mounting debt.

The decisions angered many parents and students, some of whom said the archdiocese seemed indifferent to their concerns.

A spokesman said after the news conference that O’Brien would remain active as an opponent of same-sex marriage. Last month, O’Brien urged Gov. Martin O’Malley (D) against supporting the legalization of same-sex marriage, which he described in a letter to the governor as “a goal that so deeply conflicts with your faith.”

Days later, O’Malley, who is Catholic, announced that he would introduce legislation next year to issue marriage licenses to gay couples.

— Baltimore Sun