Pope Francis will on Saturday create 21 new cardinals from five continents, including bishops from Algiers, Tehran, Tokyo and Abidjan -- many of whom may one day help choose his successor.
In the tenth such consistory since he became pope in 2013, Francis, 87, is seeking again to shape the upper echelons of the Catholic Church in his image, and consolidate his legacy as the leader of a more inclusive and global institution.
The Argentine pope -- the first pontiff from Latin America -- has championed a grassroots Church that values its faithful even far from the Vatican, and has sought to promote the clergy of developing countries to the highest ranks.
This year, Francis has selected five bishops from Latin America (Ecuador, Chile, Brazil, Peru, Argentina), and two from Africa (Ivory Coast, Algeria) to become cardinals.
The Asia-Pacific region, where Catholicism is growing the fastest, is represented with promotions of the archbishop of Tokyo and the bishop of the Ukrainian Catholic Church in Melbourne, Australia.
Francis has also selected Belgian prelate Dominique Joseph Mathieu, who serves as the archbishop of Tehran-Isfahan in Iran.
After Saturday's promotions, Francis will have chosen nearly 78 percent of the 140 so-called "elector" cardinals.
Twenty of the new group are under the age of 80, making them eligible to vote in the conclave that would be called to choose a new pope in the event of Francis' death or resignation.
But there is no guarantee that his appointments would share his views.
Cap and a ring
The pope has exclusive responsibility for naming cardinals, the so-called 'Princes of the Church', whose role is to assist him in the government or Curia of the Holy See.
Some cardinals live in Rome and hold functions within the Curia, but most continue to exercise their ministry in their dioceses.
Saturday's ceremony will begin at 4:00 pm local time (1500 GMT) within the sumptuous St. Peter's Basilica.
As is customary, the cardinals-to-be will kneel before Pope Francis to receive their biretta, or square scarlet cap, and a ring.
The ceremony will be followed by the traditional "courtesy visit", in which members of the public can meet the new cardinals, who will then gather for a mass Sunday morning at St. Peter's.
One of the new 'princes', archbishop of Algiers Jean-Paul Vesco, told AFP he expected it to be "very emotional".
The 62-year-old former lawyer said the pope's new choices offer "rich diversity, geographical and sociological" -- a "positive" step, as long the body of cardinals operate cooperatively.
Over the past decade, Francis has focused his attention on often overlooked dioceses from what he calls the "peripheries" -- including where Catholics make up a minority, such as Indonesia, the world's most populous Muslim-majority country, which he visited in September.
His pick of cardinals partially reflect these choices, and he has broken away from the custom of systematically promoting archbishops from large, prestigious dioceses such as Milan or Paris.
Vatican observers closely scrutinise the list, seeing in it a possible indication of the future priorities and values of the Church's next leader and its nearly 1.4 billion faithful.
Francis has left open the option of resigning, like his predecessor Benedict XVI, should he be unable to carry out his duties.
But despite recurring health issues, he remains very active and said for now he is going nowhere.