With thepassing of Pope Francison April 21, the speculation about who will succeed him as head of the Holy See is already in full swing. One of the front-runners, at least according to bookmakers, is Peter Erdo, the archbishop of Esztergom-Budapest.

The 72-year-old Hungarian cardinal has held several prominent roles within the Catholic Church in recent decades and was a potential candidate to become the bishop of Rome back in 2013, whenFrancisultimately was chosen.

So what chances does Erdo have to replace the Argentine? And perhaps more interestingly, what is his relationship with Hungary's increasingly authoritarian conservative prime minister, Viktor Orban?

Who Is Peter Erdo?

Make no mistake about it, Erdo is very much "papabile" -- a term used for candidates who are regarded as viable for the papacy.

Technically any baptized Catholic male is eligible, but ever since the 14th century only cardinals, the senior members of the clergy, have been selected. Currently there are 252 cardinals, but that number dwindles to 135 with voting power, as only those under 80 can cast a ballot.

Erdo could manage to secure the necessary two-thirds of the vote at the Papal Conclave that is set to commence in early May (no earlier than 16 days after the pope's passing, according to the current rules).

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His cardinal resume is glittering. Between 2006 and 2016 he headed the Council of European Episcopal Conferences, a key organization representing Europe's Catholic bishops.

This is not without significance, as European cardinals still form the biggest voting bloc in the upcoming conclave. But it's not only the European credentials he has honed.

Heading the council meant that he has been in regular contact with the African, Asian, and Latin American equivalences, building up lots of links with the Global South, seen as the emerging powerhouses of the church.

The fact that he is fluent in both Italian and Latin -- two crucial languages for higher offices in this part of Rome -- and is a recognized expert in canonical law, which governs the way the Catholic Church is run, also puts him good stead among a select few.

Perhaps his crowning achievement is to have secured the International Eucharistic Congress for his hometown, Budapest, in 2021.