In 2017, Court said tennis was "full of lesbians" and transgender children were the work of "the devil"

Margaret Court's tennis achievements are unmatched. So is the level of controversy surrounding her.

The Australian holds the record for all-time Grand Slam singles titles and 2020 is the 50th anniversary of when she won all four major titles in a calendar year.

But her views on gay marriage and transgender athletes have split opinion on how these successes should be marked.

Tennis Australia says it plans to "recognise" - rather than "celebrate" - her 1970 sweep of the Slams at this month's Australian Open, while reiterating its stance against the 77-year-old's "demeaning" personal views.

Court was a quiet champion, dominant over her sporting rivals but shy and retiring in public life. Now she finds herself at the centre of a long-running polemic set to play out its latest chapter. She is a divisive figure, branded "homophobic", "ignorant" and "dangerous" for her very publicly expressed beliefs.

So just how did a women with 64 Grand Slam singles and doubles trophies get to this point?

There was a time when Margaret Court was simply a "great champion".

Her haul of 192 career singles titles between 1960 and 1977 is a women's record and her 24 Grand Slam singles titles is an all-time record. She also shares the record with Belgium's Kim Clijsters for major titles won as a mother (three).

Her calendar Grand Slam 50 years ago came in a season where she won 21 of 27 tournaments, and 104 of 110 matches.

"She was a great athlete and an all-court player," says former French Open and Australian Open champion Nancy Richey, who reached the doubles final with Court at Roland Garros in 1969.

Court, pictured here at Wimbledon in 1973. Months later she would win her final Grand Slam singles title, with victory at the US Open

"She was as good on the baseline as she was at the net, which is a rarity. She had good groundstrokes, a good forehand, a good backhand - she was just tough.

"Most of the players were about my height - 5ft 6in or 5ft 7in - but she was about 5ft 10in or so. There were so few that had a lot of height, she was very imposing.

"She was the first one really to lift weights and she had really built up her right shoulder and arm. She had long arms, in fact her nickname was 'Arms'. She went about it almost like they do today as far as lifting weights and that kind of thing."

Court's Grand Slam singles record is close to being equalled - Serena Williams is one title away from drawing level and will get her next chance to do so at the Australian Open, which starts on Monday.

The American, 38, has been stuck on 23 for three years, with her last major victory the 2017 Australian Open, which she won while eight weeks pregnant. Since coming back from having her daughter, she has reached four Grand Slam finals but failed at the final hurdle each time, most recently in September's US Open defeat by Canadian Bianca Andreescu.

Many will point out that Court's record was set in a different period - spanning the amateur and professional eras, with only 11 of her major titles coming in the Open era. Many will argue that some of the fields were not as competitive as today. Still, the Australian's record is one Williams covets.

This milestone is "why she came back to playing tennis after having a baby and so many medical complications", Williams' coach Patrick Mouratoglou said before last year's Wimbledon final, which she lost to Simona Halep.

Court's achievements earned her multiple honours, including an induction to the International Tennis Hall of Fame, an MBE and her face on an Australian postage stamp.

She also had the Margaret Court Arena named after her at the Australian Open's Melbourne Park in 2003 - but less than a decade later there were calls for it to be renamed.

What has Court said?

Towards the end of her tennis career Court, who was brought up as a Catholic, became involved in the Pentecostal church. She was ordained as a Pentecostal minister in 1991 and went on to found her own church - the Victory Life Centre in Perth - where she is the senior minister.

Her stance against gay marriage - which was legalised in Australia in 2017 - comes from her religious beliefs, she says, and is voiced regularly in her sermons.

In 2017 she wrote an open letter to Australian airline Qantas, saying she would be boycotting it because it had become an active promoter of same-sex marriage.

"I believe in marriage as a union between a man and a woman as stated in the Bible," she wrote. "Your statement leaves me no option but to use other airlines where possible for my extensive travelling."

That same year she also said tennis was "full of lesbians", while she has also spoken against transgender athletes and branded the teaching of LGBT rights as "of the devil".

Court finds herself in the centre of controversy these days. Yet as a player, she had a reputation for being quiet and disliking the limelight.

Former champions (from left to right) Martina Navratilova, Billie Jean King, Steffi Graf, Margaret Court and Maria Bueno are honoured at Wimbledon in July 2006

Describing how she sealed her 1970 calendar Grand Slam with victory over American Rosie Casals in the US Open final, the International Tennis Hall of Fame writes: "There was no triumphant tossing of the racquet or leaping the net or falling on the court in disbelief. Court methodically and calmly walked to the net and shook Casals' hand.

"She retreated to her seat courtside $7,500 richer - which was the biggest monetary prize in women's tennis at the time - and had become a calendar year Grand Slam champion, fulfilling a dream long in the making. Court was calm, cool and composed."

She was also a nervous public speaker. Richey recalls watching the Australian having to address the Wimbledon winners' ball in 1966.

"She was petrified of doing any public speaking and she broke out in big red blotches on her chest and back," Richey says. "She got through and did it but it was not what she was comfortable doing."

Contrast that with the Reverend Margaret Court, who stands and speaks in front of her congregations - her services are also streamed online - with unwavering confidence in both herself and her views.

Only a month before this year's Australian Open, she again hit the headlines with a sermon declaring: "You know, even that LGBT in the schools, it's the devil, it's not of God."

And it reopened the debate about the country's most decorated female tennis player.

'Hiding behind her Bible'- what has the response been?

Court's opinions have been widely condemned, with 18-time Grand Slam singles champion Martina Navratilova labelling her most recent outburst "pathetic" before going on to say it was "amazing how strong her homophobia truly is".

She added: "It's outrageous and so wrong. We don't need to change or rewrite history when it comes to anyone's accomplishments but we do not need to celebrate them. Margaret Court is hiding behind her Bible as many have done before her and will do after her. Let's not keep elevating it."

Fellow great Billie Jean King, who like Navratilova is gay, is among those who have called for the Margaret Court Arena to be renamed. She says if she were competing today she would not play at the stadium.

British player Laura Robson wore a rainbow headband on the court in 2012, while in 2018 players faced repeated questions about whether they would boycott it.

No-one shunned the court in protest - in fact it was Court herself who did not attend the Australian Open two years ago, saying she had decided to go crabbing with her family instead and implying it had nothing to do with the furore surrounding her. "I don't run from things, I face them," she told the Australian Herald Sun at the time.

Martina Navratilova, in a BBC documentary, called on sport to change its rules so trans athletes are not excluded

Australian former doubles specialist Rennae Stubbs describes Court and her views as "ignorant and dangerous". LGBT rights group Stonewall says it is "sad" that she continues to voice "offensive and prejudiced" views.

"Sportspeople are considered role models to many and so anti-LGBT comments can have a hugely negative impact, particularly on younger lesbian, gay, bi and trans people," Stonewall's director of sport Robbie de Santos says.

"They make clear that LGBT people are unwelcome and so they feel they have to either hide who they are, or not take part in sport.

"Court's remarks also show us how faith is often used to justify anti-LGBT views and attitudes. This is wrong and perpetuates a myth that faith and LGBT inclusion cannot coexist.

"Faith is a big part of many LGBT people's lives, and acceptance as part of a faith community can be incredibly powerful."

Court does, though, have her supporters.

Nancy Richey - who won the Australian Open in 1967 and the French Open in 1968 but lost two US Open finals to Court, in 1966 and 1969

Nancy Richey had just opened a Christmas card from Court when she spoke to BBC Sport. She said the Australian had included a note about "how they have twisted her words and what-not in the press".

The American, who lost in two Grand Slam finals to Court, has sympathy for her former rival. She holds the same views on gay marriage. She even wrote to Tennis Australia a couple of years ago to urge them not to rename the stadium.

"It is so wrong, they put her name on there because of her great tennis career - and end of story," she says now.

"I believe, like she does, [that] marriage is between a man and a woman, that the lesbian thing is against what the Bible says it should be.

"Where she and I both come from is that that's a sin and we love the sinner. That's no different than sex before marriage, sex outside marriage - sin is a sin in God's eyes.

"I feel like her words have been twisted on occasion and what I'm telling you is the way we both think on the thing and I guess where I know I come from is you can't say anything about what we believe without having all hell break loose.

"We can't say how we feel about it, our belief about it - that to me is wrong, I should be allowed to voice my opinion and the way I see it and the way I believe and that's where she is coming from."

Television debates in Australia have been heated on the issue, while the Australian Christian Lobby has gathered more than 22,000 signatures since December on a public letter that says it stands with her and thanks her for her "boldness, despite overwhelming pressure, in speaking God's truth and standing with Christ as a public figure and Aussie icon".

And as Melbourne Park prepares to host Court for her anniversary, the debate about the player versus the person is likely to surface again.

Marking anniversary is 'no-win' situation

When Australian great Rod Laver celebrated 50 years since the second of his own Grand Slams in 2019, it was much more straightforward. He was honoured at all four of the majors, receiving replica trophies and ovations.

Before plans were announced for her own big year, Court had asked to be recognised in the same way as Laver, saying: "I think I should be invited [to the Australian Open]. I hope they [Tennis Australia] would pay my way to come like they paid for him, and honour me. If they are not going to do that, I don't really want to come."

When Tennis Australia eventually announced it would be recognising her achievements it took the unusual step of distancing itself from her views at the same time - effectively tagging a disclaimer on the end of the press release, saying: "We cannot condone views that fracture our incredible tennis community, nor indeed, the wider community."

Court, pictured in January 2003, when the ground at Melbourne Park was re-named after her

It added there was "an important distinction" between "recognising champions and celebrating heroes".

That led to Court's four children releasing a joint statement, saying: "It is hard for her family to understand how her current lifestyle would possibly affect her tennis career in any way.

"It is disappointing to see Tennis Australia in the open letter amalgamating her sporting career which she won for the nation."

It should, perhaps, be pointed out that Court herself does not necessarily keep her tennis and her other life separate - her profile page on her church website includes an invitation to buy her autobiography about "the greatest tennis player of all time".

Tennis Australia has yet to detail exactly how it will be marking the 1970 Grand Slam 50-year anniversary. It says a mini-documentary will be released during the Australian Open, there will be a feature on her achievements in the tournament programme and some "in-stadium entertainment that takes the audience back to 1970 and Margaret's historic win".

Whatever the governing body does, it is hard to see it happening without criticism or debate.

"Tennis Australia was in a no-win situation in some respects," Stubbs tells BBC Sport.

"I would have loved for them to not have honoured her as a respect for all the people that she has denigrated over the years, including some of our own players, but I understand they were in a difficult situation. I hope it's the last one they have to make when it comes to Margaret."

The other three Grand Slams have yet to decide what they will do, with only Wimbledon saying: "We will be celebrating the 50th anniversary of her win across our content plans as we did with Rod."

They all have the luxury of waiting to see what the reaction is in Melbourne first.

What will the reaction be at the Australian Open?

The plans for marking her anniversary have been so vague that it is not even clear if Court will be presented to the public and so it is hard to know what kind of reception she might get.

"The public may yet be taken out of the equation if Tennis Australia feel nervous enough about any potential reaction," says Mike Hytner, sports editor of Australian newspaper The Guardian.

Police officers attempt to stop protesters from storming the back entrance to Melbourne's Athenaeum club, where Court was the keynote speaker on 22 June 2017

"I can't imagine her getting booed, to be honest, certainly not on Rod Laver Arena, which is generally less rowdy than the outer courts can be.

"There were strong feelings about renaming the arena but there is more of a pervading sense now that her views are irrelevant. Most of the country is ambivalent to her."

Asked last month whether the Australian Open was bracing itself for controversy, Tennis Australia chief Craig Tiley told reporters: "That's going to be up to the Australian fans. There are no fans in the world that are like Australian fans. I'll leave their response up to them."

Tiley, though, did say Court would not be presenting the women's singles trophy - although Laver also had no trophy-presenting duties in Melbourne in his anniversary year, so it cannot be viewed as a snub as such.

Stubbs says some people may well choose to do just that, though.

"I think the people that want to honour her on that day have every right to," she says. "I also suspect there will be many people and players that will not be there to honour her and that is their right also."