Five years ago, 15 men travelled from the southern tip of Africa to the upper edges of the northern hemisphere on a mission to claim the Test mace. Only five have returned.

Hashim Amla, JP Duminy, Faf du Plessis, Morne Morkel and Vernon Philander are the only members of South Africa's 2012 Test tour of England that are back in 2017. This time, the incentive is not quite as impressive - even if South Africa win the series 4-0, they will not be able to move from their No.2 spot though they would close the gap on India to one point - but the interest is just as high.

Even in an environment where, as the MCC put it less than an hour after South Africa's training session, international cricket is facing a "looming potential crisis", playing Test cricket in England is still a big deal for South Africa. It's where names are made (think Graeme Smith), it's where records are remembered (think Hashim Amla) and "it's a tour you want to be part of," according to Russell Domingo, South Africa's coach. And why not?

This millennium, South Africa have had more success in England than any other touring team. They are the only visiting side to have won more than they have lost and they have triumphed twice as many times as they have been defeated. Since 2000, South Africa have not lost a series in England, with a drawn series and two victories, each historic in their own right. In 2008, South Africa claimed a first series win in England since readmission; in 2012, they took the top Test ranking too.

Settled squads and serious planning have been important ingredients in their performances. In 2012, they took that to the extreme and prepared with a camp in Switzerland under the guidance of adventurer Mike Horn. South Africa trekked through the Alps to build character and cycled through the town of Chateau-d'Oex to develop endurance. They came to England so solid in their mindset that not even a career-ending injury to Mark Boucher in the first tour game could shake them. This time, some would argue, they're both shaken and stirred.

South Africa's build-up to the Tests has involved nothing but cricket. They've played in an ODI series, in an ICC tournament and a T20 series, and have lost in all of them. They've had to deal with whispers about the future of their ODI captain and louder calls over the continuation (or not) of their coach. It's far from the serenity of Switzerland and, you would think, far from an ideal environment in which to begin a big series.

But Domingo, who has since confirmed his reapplication for his post, has to say that the perceived current climate - of a team down on its luck and lacking motivation - is merely a consequence of circumstance. "It was always going to be a long summer, it was always going to be a long three months in England whether you are winning or losing," he said. "But there are a whole host of new players that will bring unbelievable energy."

Although that is not strictly speaking the case, because those who are new to the squad have either been with the A side or on the county circuit, a change in personnel usually refreshes an outfit. Vernon Philander is one of those "new players" who was not part of any of the limited-overs losses and also used the word "energy" to describe the mood but, curiously, he harked back to the team-building exercise held in August last year as a key factor in preparation

"Thinking back to 2012, we had a culture camp before we came here. We had something similar a couple of months ago. There's a whole lot of new faces which brings a whole lot of new energy into the side. As long as you have energy to burn there's excitement going into the Test series," Philander said.

The team-building exercise Philander is referring to was held almost a year ago, ahead of the 2016-17 season. It's unlikely that an event held that long ago would still have an effect on the team now, but consider the initial outcomes. South Africa, then ranked No. 7 in Test cricket and fresh off being booted out of a tri-series in the Caribbean in the league stage, won all eight trophies on offer last season.

They climbed to No.2 in Tests with wins over New Zealand (home and away) Australia (away) and Sri Lanka (home). They rose to No.1 in ODIs with whitewashes of Australia and Sri Lanka and though that counted for nothing come major-tournament time, it earned them a lot of goodwill. Before leaving for the UK, South Africa were considered a team on the up. Though their white-ball results have led to the return of some past concerns over their temperament under pressure, South Africa have always seemed a completely different unit as a Test side. They thrive when it's tough.

Not Ashwell Prince's broken thumb in Australia in 2008, not Smith's broken hand later in the series, not Jacques Kallis' broken ribs against India at home in early 2011, not Dale Steyn's broken shoulder against Australia last year - none of these have been able to stop South Africa from battling. In fact, things like that have spurred them on.

There are no major injuries this time but there are many absentees. Steyn is still recovering, de Villiers is on a sabbatical, and the new leader du Plessis has been forced to sit out the first Test after the arrival of his first child. While South Africa have got used to being without de Villiers and Steyn, losing du Plessis will test them in another way. It will ask them to be as good as they have been before without something they have always had before: a strong leader.

That's not to say Dean Elgar, whose personality is reminiscent of Smith's in many ways, won't take to the job; it is simply to point out that he has not done it much before. In fact, Elgar has only captained in seven first-class games. It is also a comment on the lack of seniority in the ranks. Hashim Amla is notoriously reluctant to take charge, JP Duminy is the only other senior batsman and is in under severe pressure to retain his place, and Morne Morkel is the only quick to have played more than 50 Tests.

Put another way, South Africa's depth will be tested more than it ever has in England. Heino Kuhn and Aiden Markram are yet to be capped; Theunis de Bruyn has only Test to his name; Quinton de Kock, Keshav Maharaj and Kagiso Rabada have each played less than 20 Tests, and Temba Bavuma will play his 21st at Lord's. The inexperience could be worrying but the potential is promising.

Fifteen men have traveled from the southern tip of Africa to the upper edges of the northern hemisphere on a mission to prove their mettle. The next six weeks will give us a clue as to how many will return next time.

Firdose Moonda is ESPNcricinfo's South Africa correspondent