Hashim Amla is calmness personified, so much so that in his 12 years as an international cricketer, he has been cross precisely once. Okay, twice, but it was about the same thing.

Last November, when Faf du Plessis was taking heat from the Australian media for using mint-infused saliva to shine the ball, Amla was the spokesperson for the entire squad as South Africa mounted a united defence at the MCG.

An angry Amla said they believed the allegations were "a joke" and that du Plessis had done "absolutely nothing wrong". He resorted to a wry line himself. "Do you want me to brush my teeth every time I walk out onto the field?" he asked one reporter.

Two days later, when du Plessis was trailed by an enthusiastic television news crew at Perth airport, Amla took to Twitter to scold the journalist for "provocative behaviour" and said, "Ask a man with manners and courtesy and you will probably get a response."

Hashim Amla watches a bouncer go by during his 96 Gallo Images

All that occurred during one of the leanest patches in Amla's glittering career. Perhaps even he gets frustrated sometimes. As Kagiso Rabada put it, Amla is "not a robot".

There must be times when he gets excited or overwhelmed, and with good reason. He has three children under the age of five, for a start, and spends months living out of suitcases and hotel rooms, which is enough to stir emotions in anyone.

In recent years Amla has provided more glimpses into his personality and become more outspoken. When he resigned the Test captaincy, he spoke about the difficulties that players of colour face, but he remains largely a private individual. He turned down the offer of a special dinner in his honour ahead of his 100th Test. The match is probably as important to him as his first, 21st or 71st game.

So who is Hashim Amla, really? ESPNcricinfo spoke to current and former team-mates Dale Steyn, Stephen Cook, Herschelle Gibbs and Robin Peterson, a former captain, Graeme Smith, and a former coach, Gary Kirsten, to try and find out.

Graeme Smith walks back with Hashim Amla after taking his team to a win Getty Images

A believer

Amla's commitment to Islam was one of the first things the world learnt about him when he refused to wear the Castle logo on his kit, but even as a teenager he was rooted in religion. On an Under-19 tour, Amla asked room-mate Peterson whether he would mind if Amla stayed up at night and woke up early to pray. "I told him I had absolutely no problem with that," Peterson, who had extended family who were Muslim and was well acquainted with the faith, said.

Amla's commitment to his faith inspired many of his team-mates, not just for his dedication but for how he managed to make it all encompassing. "As much as he is diligent and disciplined in his own faith, he is also extremely tolerant of other people's beliefs," Kirsten said. "That's what makes him the perfect team man."

A batsman with a strange backlift

It was thought that Amla's unusual backlift - it began from the direction of gully instead of straight behind him - might hold him back. Gibbs, who despite his flamboyance in life had started with an orthodox approach to cricket, said he was among those who doubted. "I wasn't sure about him when I first saw him bat," he said.

But Graeme Smith, who also had an unorthodox technique, liked what he saw. "I am a big fan of different styles of cricketers, different grips, and different ways of ways of doing things," he said. "That means that captains have to set fields differently and think of other ways to get people out. It makes it interesting."

Mitchell Johnson bowls to Hashim Amla Getty Images

A student

What set Amla apart from his peers was his insatiable appetite for learning, especially about cricket. He constantly sought to improve. "He is a real student of the game and he has an enquiring mind," Kirsten said. "He has always wanted to find ways to grow in the game and to engage in discussions about different ways of playing."

Amla captained South Africa in the 2002 Under-19 World Cup and made the final. Cook was part of that team. "Hylton Ackerman senior was the coach and he spoke of Hashim's cricketing knowledge beyond his years," Cook said. "Hashim had such a good feel for the game and where it was going, and what methods and tactics to use then as a captain."

A diligent trainer

To do that Amla had to spend hours in the nets, to ensure he was as ready as he could be. For a captain, that was a dream; for a coach, maybe less so. "If you can find mature people who get themselves into places where they are prepared to perform as well as possible, that is a bonus," Smith said. "He has always been a very driven guy. He is meticulous and works hard at the nets. I have never met anyone who hits more balls, he is an assistant coach's nightmare."

Part of Amla's routine is to take a bag of golf balls to practice and hit them with a stump to fine-tune his eye. During the tour of New Zealand in 2012, Amla asked Kirsten to do the golf-ball throwdowns.

"After I had sent down about ten, he came to me and said, 'You've got to throw harder than that. You've got to make it more difficult for me,'" Kirsten said. "I just realised that not only did he want me to send the ball down quickly, he also wanted it on a good length. He really wanted to be challenged."

Kirsten has only seen one other player train as hard: Sachin Tendulkar.

Hashim Amla pads up for a net session AFP

Amla's approach to practice has not changed, and as recently as the Australia tour he was training as hard as ever. South Africa were preparing for their first day-night Test with a pink ball and Dale Steyn was bowling to Amla. "After that session, I walked into the change room and I said, 'Either I'm shit, or that net is really flat, because Hashim just bliksemmed [smacked] me everywhere.'"

Amla is one of two batsmen Steyn does not enjoy bowling to in the nets. AB de Villiers is the other, but for different reasons. "AB makes it look really easy, but he doesn't play as many shots. Hashim is aggressive in the nets. He wants to feel bat on ball. I never walk away from a net feeling confident after I've bowled to Hashim."

A partner

All that practice made Amla the near-perfect partner. He features in South Africa's two most successful pairings: 3923 runs with Jacques Kallis at 61.29 per partnership, and 3658 runs with Smith at 57.15. Smith particularly enjoyed batting with Amla because "he scored runs at a great tempo and transferred pressure a lot".

Of all the stands they shared, Smith picked the 195 against Australia at Newlands in November 2011, when South Africa chased 236 for victory, as the highlight. "We complemented each other pretty well. Our Afrikaans was probably also as bad as each other's, so mostly we had to communicate in English."

That's not to say all of Amla's partners had much in common with him. Gibbs, who partnered Amla in six Test innings early in his career, joked: "We didn't do much together. We never even shared a milkshake."

Jacques Kallis and Hashim Amla put on 330 runs for the third wicket Getty Images

A batsman without obvious weaknesses

Steyn thought he had it figured, but says he might have been wrong. "I got him twice off slower balls early in his career so I thought this was the way to do it," he said. "Then I tried it in the CPL and he got hold of me. With Dwayne Bravo, he hit my last over for 22.

"He's quite clever. He walks across the stumps and he flicks you to the leg side. He stands still and smokes you through the covers. With players like that you've almost got to double-bluff him and maybe bowl leg side and then try a wide Yorker. You need to gamble. The truth is that if you miss your execution or even if you hit it, he can punish you."

A captain

Amla was a surprise choice to replace Smith as Test captain, because he had shown reluctance to lead earlier in his career. Apart from stepping aside as Dolphins captain in the mid 2000s, Amla also walked away from South Africa's limited-overs vice-captaincy in 2013 but then made himself available to lead the Test team. Steyn was one of his greatest supporters.

"I enjoyed his captaincy. He was quite aggressive," Steyn said. "In his first series in charge, in Sri Lanka, he called us into a huddle and told us these words - I can't remember exactly what they were but it was pretty similar to the team song we have now - and he said we had to say this and from that moment, when we went on to the field, we would dominate. It didn't matter what had happened before or after that. I thought it was quite nice. I thought he would be a quiet captain but he was quite vocal and after that series, I thought he had the job nailed down."

Eighteen months later, Amla stood down. Smith was not entirely surprised. "If I think honestly, I would never have pushed him into captaincy. The space that he operates in is that he has his routines, and captaincy would have added extra pressure.

"When you're the captain, you don't have time to be as meticulous, you have to go straight from training to a selection meeting and then to sponsors, it's a never-ending story. He likes to be thoughtful, to consider things and go through routines, and I think he recognised that it was not working for him."

Hashim Amla announces his resignation as South Africa captain Getty Images

A player worth more than his runs

Amla has gone back to being part of the team's senior core, a space in which he excels. The work he does behind the scenes has earned the praise of many, including some of the newer players.

"He is so welcoming and such a voice of calm. When situations are tricky and when people need to be grounded, he is the voice of reason," Cook said. "He brings confidence to the group. Although he didn't score many runs in Australia, the impact he had on the other guys performing was immense. His experience of the wickets in Australia, how to deal with the Australians, with the variety of difficulties, was a big help to guys like myself. He plays a vital role, whether he scores 0 or 100. He starts on 30 because he has added 30 runs in value by his experience."

Amla is generous in sharing his knowledge, more so than other players. "So many guys have got experience and got knowledge and hold it to themselves and use it as their secret weapon," Cook said, "Whereas Hashim is one of those guys who just gives it out freely and for the betterment of all."

A personality

There is more to Amla than cricket. "He surprises you with the things he is interested in," Smith said. "He really likes to surf, for example." And he has struck up a close friendship with New Zealand rugby star Sonny-Bill Williams. Could you find a more unlikely pair?

Amla's sense of humour is much loved too. "He is the funniest guy. He has a very dry sense of humour," Steyn said. "And he is always listening. He may just be sitting there quietly, cleaning his bat, but he will be taking in everything, and then in a couple of days he will drop a bombshell and everyone will just laugh."

Steyn doesn't mind that Amla is a cleanliness freak, either. "He is a true professional. His kit is pristine. I enjoy sitting next to him because I hate having a messy change-room."

Or that he is well connected. "He knows people all around the world, and he always has people cooking a meal, and he always invites everyone," Steyn said. "Boys on tour love a home-cooked meal."

Hashim Amla is bowled by Josh Hazlewood Cricket Australia/Getty Images

A batsman going through a rough phase

After ten Test innings without a half-century - 13 without a hundred - Amla looks to have lost some of his touch. He is getting out to good balls but also to bad shots; some impatience seems to have crept into his game. Most of his team-mates are not worried, and say a big score is around the corner. Steyn is one of them and he even thinks that Amla could benefit from this struggle.

"This is one of those phases everyone goes through. He has been getting some good balls, which happens, but also he has been holding his pose a little longer, and maybe nicking balls that otherwise he would play and miss at," Steyn said. "He needs a bit of luck. If he is going to nick, he needs it to go through the slips and for four to get the ball rolling.

"He will probably tell you that it's nice to be out of form. As funny as that sounds, you want to experience all aspects of cricket. When you're at the top of your game, obviously it's good, but when you're at rock bottom, you need to try and dig yourself out. But good players don't go bad overnight."

A cricketer with a future

With 100 Tests to his name and more than a decade in the game, how long does Amla have left? For Kirsten, it's about goals. "At some point when performance becomes indifferent, you have to ask yourself what more he wants to achieve. Does he want to play another 50 Tests, another 20? These great players can always come back to great form."

For Smith, there is no question. At least not now. "At the moment, South Africa cannot afford to be without Amla. He is just too good a player and once he gets some luck, he is going to hurt somebody."