On Wednesday, the cardinals will convene to conclave and only when white smoke rises to the sky has a new pope been elected after the deceased Pope Francis.
It's not the only event that attracts visitors to Rome this week.
Three kilometers north of the Vatican City, Italian world number one Jannik Sinner is back on the tennis court – his three-month doping suspension has expired.
Serena Williams critical
A short suspension that has led competitors and retired stars to claim that Sinner has been treated favorably.
We must be honest – I would have lost Grand Slam titles, said Serena Williams to Time Magazine in an interview published in April.
Williams says she has thought about what her former competitor Maria Sharapova thinks. The Russian was banned for two years in 2016, but the Court of Arbitration for Sport (CAS) shortened the sentence to 15 months. This because it was deemed that she had used meldonium, which was banned on January 1, 2016, for medical purposes.
I can't help but think of Maria. I feel with her, says Williams.
In February, Sinner and the International Anti-Doping Agency WADA reached an agreement that the star would be banned for three months. He is said to have unintentionally ingested the anabolic steroid clostebol, which he tested positive for in March last year.
Sinner now says that he initially did not want to accept any suspension at all.
"A simple guy"
But sometimes you have to choose the lesser evil. It's over now. I'm glad to be playing tennis again, says Sinner, who hasn't played a match since he won the Grand Slam tournament Australian Open in January.
He seems to be welcomed with open arms by the audience.
Ahead of his return to the ATP tournament in Rome – the last clay test before the Grand Slam tournament French Open in Paris – people have started playing with the classic Latin words uttered when the cardinals have made their choice: Habemus papam! (We have a pope!), reports news agency AP.
In tennis language: Habemus Sinner.
To be honest, I'm a simple 23-year-old guy. I'm good at playing tennis, but I'm not changing the world, says the world number one who is expected to enter the second round of the home tournament on Saturday.
Tennis star Jannik Sinner left two positive doping tests in March last year.
He was initially completely acquitted by the International Tennis Federation since it was shown that he had unintentionally ingested the anabolic steroid clostebol.
It was said to have occurred through a massage by his physiotherapist, who had injured his finger and therefore used a salve for the injury.
The International Anti-Doping Agency WADA appealed the decision and wanted to see Sinner banned for two years. An agreement was reached and in February the Italian was banned for three months.
WADA acknowledges that Sinner did not intend to cheat and that the contamination was not performance-enhancing. He is not considered responsible for having ingested clostebol.
The doping suspension expired on Monday.
