Charismatic and controversial: Novak Djokovic, undisputed king of tennis

Novak Djokovic, who won a record-equalling 23rd Grand Slam title on Sunday, is driven on through controversy by his determination to be the greatest ever.

The Serb's victory over Casper Ruud in the French Open final took him past great rival Rafael Nadal at the top of the list of all-time men's major champions.

For 36-year-old Djokovic, it matters to be the best, and he has a strong sense of his historical place in tennis.

But he also keeps ploughing on through the highs and lows because it is "a great school of life".

From one legend to another ??#RolandGarros | @RafaelNadal pic.twitter.com/IOLZduLHYW

While Nadal and now-retired Roger Federer are widely admired, Djokovic continues to divide as well as unite.

His staggering achievements on the court have often been overshadowed by blunders and missteps off it.

The latest was in the first week of the French Open when he wrote "Kosovo is the heart of Serbia" on a courtside TV camera lens as ethnic tensions were again rising in the Balkans.

On court, he was booed for fist-pumping as semi-final rival Carlos Alcaraz wilted with cramping.

"I don't mind. It's not the first; probably not the last. I'll just keep winning," said Djokovic.

On Sunday he hinted at a run at the first calendar Grand Slam since 1969.

When asked if his goal now was to win a "24th, 25th" Grand Slam title, he told France 2 TV: "Yes, why not. I feel good this year, I won the two Grand Slams that I played (Melbourne then Roland Garros). So why not?

"I'm going to look to win Wimbledon again. I've won the last four Wimbledons, I feel good on the grass."

Rod Laver in 1969 was the last man to sweep all four Slams - Australian Open, French Open, Wimbledon and the US Open - in the same year.

Djokovic came agonisingly close to