On Thursday of last week Diarmuid Martin's secretary at the Pontifical Council for Justice and Peace received a phone call from Ireland from a gentleman called Bono who wished to talk to the bishopelect about a charitable enterprise in which he is involved.
Receiving phone calls from famous people is all in the line of daily business for Diarmuid Martin. Since taking up the position of under-secretary (subsequently Secretary) at Justice and Peace in 1985, Mgr Martin has been a key, behind-the-scenes figure in what is one of the most dynamic departments in the Vatican, a department furthermore whose very raison d'etre takes it into daily dialogue, contact and sometimes conflict with just about every socio-political power bloc in the modern world.
Dublin-born Diarmuid Martin's appointment last week as Titular Bishop of Glendalough (he will be consecrated by the Pope in St Peter's Basilica on January 6th) is emphatic Vatican recognition for what, in other organisations, might be called service in the field.
Although he says that at 53 he is young by Vatican standards to be made bishop, Vatican insiders this week suggested that such has been his contribution that his promotion was long overdue.
For much of the last decade, Mgr Martin has been a largely unseen Vatican mover and shaker. However, the fact that he has either led or been a senior figure on Vatican delegations at the set-piece United Nations conferences of the 1990s on Population (Cairo), Women (Beijing), Habitat (Istanbul) and the Environment (Rio de Janeiro) says much about his standing in the Holy See.
With typical modesty, he says he got the jobs because he speaks English. However, one long-time Vaticanologist, the Rome-based American reporter John Thavis, says it's more serious than that.
"When the Vatican needs someone with political savvy, Diarmuid Martin is the choice. He is very sharp, he knows his brief very, very well and [at the UN conferences] he was nothing less than a guiding light," he suggests.
Diarmuid Martin's affability and command of English have long made him a target for visiting journalists in Rome. His good nature occasionally sees him grant the interview, but such is his theological orthodoxy that journalists never come away with controversial soundbites.
Mgr Martin has worked in the Vatican, either at the Council for the Family or at Justice and Peace, since 1977 when someone suggested to the late Cardinal Benelli that he should look at a young Irish priest, recently ordained and then studying in Rome, who spoke excellent German and Italian as well as English (he now adds Spanish, Portuguese and French to the list). The then archbishop of Dublin, Dermot Ryan, gave the go-ahead, and the new boy soon found himself in an empty office with a typewriter and no paper.
Eight years later in 1985, Mgr Martin was transferred to Justice and Peace, where he established a reputation for being what one Rome diplomat this week called "a lucid, clear and highly skilful Vatican representative with impressive knowledge of his subject matter".
In theory, the basic role of the Council for Justice and Peace is to promote, develop and update the Catholic Church's social teachings, while also keeping a wary eye on human rights and war situations. In practice this has meant that during much of the last decade Justice and Peace has fulfilled the role of Vatican troubleshooter.
The extent to which the Martin finger sits on the pulse of a complex international crisis can be surprising. The bishop-elect has been a friend of this correspondent and his family since we moved to Italy 13 years ago.
A couple of years ago I showed him around my office and he noticed the script of a short radio broadcast done that morning on a visit to Rome by President Julius Nyerere of Tanzania in his role as international mediator in Burundi.
He glanced briefly at the piece and commented: "Yes, I had dinner with him last night and what you say there is, more or less, what he's here for."
Diarmuid Martin plays down the possible dangers attached to his work but, for all that, he has been in some hairy situations. He admits he felt just a little exposed when travelling to the disputed, Indonesian-annexed territory of East Timor recently in an Indonesian military helicopter and accompanied by the Commander-in-Chief of Indonesian forces in East Timor. Likewise, he recalls a 1992 meeting in Sarajevo with President Alija Izetbegovic of Bosnia and his advisers that was carried out against a background of heavy artillery and small-arms fire, noise of which he was certainly aware but which seemed to have no effect on his interlocutors. Like many observers, too, he found a visit to Rwanda deeply disturbing.
Although he has been a largely unseen Vatican diplomat, Mgr Martin did inevitably find himself in a sort of limelight at the above-mentioned UN conferences. These were nothing less than extremely difficult away fixtures where he was sent to fight the good fight, often finding himself in the eye of the storm as the Catholic Church's teachings on sexual morality both enraged those with a liberal agenda and on occasions (in Cairo and Beijing) threatened to scupper the entire conference.
He now says that, yes, those meetings were often tough and that occasionally "bad feeling" was generated but that he has nonetheless maintained both a working contact and valid friendships with members of delegations (for instance, with the UN Population Division) who certainly do not share the Vatican's viewpoint.
As bishop, Diarmuid Martin can no longer be considered a behind-the-scenes figure, nor is he likely, as he puts it, to be pitched into the fray quite so readily. On the other hand, he is expected to remain at Justice and Peace where he will now bring the full weight of his bishop's office to bear on two questions which greatly engage him, Third World debt and the arms trade. He now commands a 20-strong staff, one of whom is engaged full-time in surfing the Internet for information related to council concerns.
Diarmuid Martin now regularly meets senior officials in both the International Monetary Fund (IMF) and World Bank - he addressed a major IMF seminar in Washington in June - in an attempt to find common ground between the Pope's call for Third World debt to be largely waived and the view of many modern economists that gross inequality creates dangerous social tensions that are bad for business.
Ask him if he is the Vatican's chief negotiator with the World Bank and he says: "No, I'm just one of those most directly involved in conversations with the World Bank."
Over the next decade, the international community is likely to find itself involved in more of these Vatican conversations with Bishop Martin.