Burly and tall, Marcinkus made a reassuring papal bodyguard
The American prelate Paul Marcinkus' rise to prominence as the Vatican's chief banker was the result of a lucky break.
He had no experience of international banking prior to his appointment in 1971, his sole preparation for which had been a short crash course in banking at Harvard University.
As a young English-speaking minor official assigned to the Secretariat of State at the Vatican, Paul Marcinkus had been signalled to Pope Paul VI as a suitable organiser of papal travel arrangements.
Pope Paul had decided to make a three-day, ground-breaking trip to Jerusalem and Jordan in January 1964.
This was the first papal trip outside Italy since the Napoleonic Wars.
No-one quite knew what a security nightmare this was going to be, but Monsignor Marcinkus ensured the success of the trip, remaining constantly and reassuringly at the Pope's side.
Marcinkus was a prelate with a presence.
Burly and 1.95m (6ft 5in) tall, he instantly became an expert and reassuring bodyguard to the Pope.
Pope Paul VI appointed Marcinkus the chief banker
He proved competent at handling complex airline charter and security arrangements for what turned out to be a series of nine international journeys which took Pope Paul VI to India, Latin America, to the United Nations in New York, and even to Hong Kong and Australia over the next six years.
After Pope Paul VI stopped travelling in 1970, Paul Marcinkus was rewarded with promotion to the rank of archbishop and a prestigious new job, head of the Vatican's bank, the Institute for the Works of Religion.
He was to remain in this post for the next 19 years.
During the 1970s, however, Marcinkus, a keen golfer in his spare time, committed some serious errors of financial judgment.
He took advice on investment policy from two Italian bankers who had become his golfing chums.
They later turned out to be important crooks.
Michele Sindona, a Sicilian banker sentenced to 25 years in jail in the United States for bank fraud, died of poisoning in an Italian jail after being extradited back home.
Roberto Calvi, a Catholic banker whose Banco Ambrosiano went into liquidation causing losses to the Vatican Bank of $240 million (£137m) was most probably murdered in London - on orders of the Sicilian Mafia.
After the deaths of Paul VI and his successor John Paul I, Marcinkus was asked by Pope John Paul II, elected in 1978, to organise his travels, which were on a much larger and more frequent scale.
So while continuing his job as chief Vatican banker, Marcinkus helped carry out complicated reconnaissance trips to prepare papal visits to more than 20 different countries around the world.
The attempt on the Pope's life in May 1981 stopped John Paul II's travels for the rest of that year but by the following year the Pope had recovered his strength sufficiently to resume his journeys.
Marcinkus: a key travel organiser for Paul VI and John Paul II
In May 1982 we, the Vatican's international press corps, were back on the road again, this time in Portugal, where John Paul II visited the Catholic shrine to the Virgin Mary at Fatima to offer thanks for what he regarded as a miraculous escape from death.
After worshipping at the shrine, the Pope narrowly escaped another attempt on his life.
A Spanish priest who, it later transpired, was suffering from serious psychiatric problems, suddenly lunged at him with a knife.
Marcinkus, at the Pope's side as always, threw himself on the assailant who was quickly handed over to Portuguese police.
I rang the archbishop later that evening to check reports that were coming out about the incident.
"No," he told me, "nothing happened."
The following day local TV transmitted pictures of the priest brandishing a knife at the Pope and we all saw how the archbishop had apparently saved the Pope's life.
Marcinkus came the following night to the Lisbon hotel where the Vatican press were staying.
I asked him to clear up the discrepancy between what we had all seen on TV and his previous denial that anything had happened.
"Oh, you know," he said, with a twinkle in his eye, "you can't always believe everything you see on TV."