The death of Pope Emeritus Benedict XVI on the last day of 2022 marked the end of an awkward period in the history of the Holy See — a time when two popes coexisted. The longer-term effects of the double-headed papacy remain to be seen — along with whether Francis, who was elected when Benedict retired in 2013, can now reign unshackled by the politesse demanded by the august but often inimical presence of his predecessor.

The career of Joseph Ratzinger, however, is one that will benefit the study of how retirement can be wielded as a strategy to further one’s ambitions.

Before he became Benedict XVI, Cardinal Ratzinger ran what was once known as the Office of the Inquisition, renamed the Congregation for the Doctrine of the Faith. It had long lost its blood-curdling reputation, but the German cardinal’s disapproval could still strike terror — and silence — in theologians, priests and would-be interpreters of Roman Catholic doctrine. He was one of the most powerful prelates in the Vatican of John Paul II, rigorously defending the charismatic, Polish-born pope’s conservative, sometimes atavistic, perspectives. As such, Ratzinger was always among the papabile, the men most likely to become the next pontiff.

The intimidating reputation — the German press dubbed him the panzerkardinal — overshadowed his vast erudition, cultural sophistication and bureaucratic efficiency. He must have been aware he was feared more than loved. In the twilight of John Paul’s more than quarter-century reign, the cardinal let it be known that he no longer wished to be in the running for the top job. Indeed, Vatican insiders said John Paul had lived too long for the Church to want to elect his ideological enforcer. They wanted a fresh face. Ratzinger was himself too old, they said; his time had passed.

Except it had not.

The Vatican’s corporate structure was one that could be manipulated by insiders such as Ratzinger who were familiar with its Byzantine levers of power and who knew how to elucidate and exploit what may be called its mission statement. When they want to take action, they usually get results. In such organisations, longevity and age are assets.

At the very end of December 2004 — a little more than three months before John Paul died — Ratzinger sprang back into action as a contender. He appeared to have softened his hardline stance, for example, not issuing orders to refuse Holy Communion to American Catholic politicians — like Joe Biden — who supported a woman’s right to choose.

To arguments that he was too old, Ratzinger gave interviews saying that future popes must consider the option of retiring — a choice his friend, John Paul, who was suffering the symptoms of Parkinson’s, refused to entertain. The implied message: if Ratzinger became Pope, he would retire rather than subject the Church to any indecisiveness under an ailing pontiff. Finally, in a political masterstroke, he delivered a tour de force of a sermon at a gathering of papabile, establishing himself as the intellect to beat in a papal conclave trying to divine the intentions of the Holy Spirit.

On April 19, 2005 — 17 days after John Paul died — Ratzinger was elected Supreme Pontiff of the Roman Catholic Church on the fourth ballot. In contrast to most of the drawn-out contests in the Sistine Chapel, it took just two days to seal his victory.

In February 2013, he kept his promise to retire the moment he felt his health was failing, becoming the first pope to give up the throne in six centuries. His papacy had not been a resounding success. Benedict began cleaning up the soul-wrecking scandal of priest sexual abuse that John Paul had refused to deal with; but as a longtime player in the Roman curia, Ratzinger had been part of what, to be charitable, was the wilful Vatican ignorance of the crimes. His sympathy for traditionalist Catholic rituals that were set aside after the reforms of the Second Vatican Council in the early 1960s was also controversial, as were his positions on birth control and homosexuality.

As an ambitious prelate, Ratzinger supported Vatican II, aligning himself with the more conservative part of the movement. The balancing act between his faction and more liberal reformers has consumed Roman Catholicism. It can be seen in the evolution of the names of the popes: first was John XXIII who convened the reformist council; he was succeeded by the more cautious Paul VI, after whom came John Paul I — a name chosen to reconcile the legacies — but that pontiff reigned only 33 days.

At his election, Karol Wojtyla chose to become John Paul II as a tribute to the tragically short pontificate, but the Polish pope’s theology was hardline and conservative. In choosing Benedict, Ratzinger opted out of the game of compromise and aimed for a rigorous continuity with the ideas of the second John Paul. When he became Pope, Archbishop Jorge Mario Bergoglio of Buenos Aires chose the name Francis — the Church’s most popular, barefoot saint — as a promise of a more open, less regal church.

That is where the contest stood — until Ratzinger died last week. But this is not the end of the rivalry.

Benedict was playing the long, if not the eternal, game. When he retired, he held on to the autocratic aura of the papacy: he continued to wear papal white and went on living in the Vatican, not heading back to his native Bavaria as a humble priest to write books. When the news of Benedict stepping down broke in 2013 — and before Bergoglio was elected as Francis two months later — I wrote a cover story for Time magazine entitled “The Once and Future Pope”. I posited that Benedict in retirement would continue to be influential because any new pope would have to be deferential to his policies and predilections. The new pontiff could not afford to be seen insulting his living predecessor.

Francis did push out several Benedict appointees from their positions of power. But even though the new pope produced liberal soundbites and exuded more charisma than Benedict, he could not afford any big policy breaks. Indeed, the retired pope became a tacit but persistent symbol of resistance to changes envisioned by his successor.

By withdrawing — twice — Joseph Ratzinger/Benedict XVI reinforced his influence on the future of the Catholic Church, perhaps more than any other prelate in the past century and a half. He was not supposed to have become the Pope. And then he was supposed to have gone into quiet retirement — an historical asterisk. He may now be more powerful in death. Indeed, his books and theological writings have gained in prestige and become even more widely read, profiting from the unprecedented extension of his papal aura. He lived more than eight years beyond his pontificate.

Benedict’s example of retirement now confronts Francis, whose own health is beginning to decline. The reigning pope said he has already pre-written a resignation in case he should be incapacitated. If he also retires with some modicum of mental acuity, may Francis try to exude the same kind of influence as Benedict? Since becoming pope, Francis has been packing the College of Cardinals with his appointees to help ensure the election of a like-minded successor. Benedict did the same — but an active retirement ensured he could manage his legacy.

• Howard Chua-Eoan is the international editor of Bloomberg Opinion