Mark Wood picked nine wickets in Johannesburg Test © Getty

Given the structural issues hampering South African cricket, the players they are missing and their unsightly run of form during the past 12 months, it would be easy to diminish the series victory England sealed on Monday afternoon at the Wanderers. It would be easy to write it off as a bit of a gimme, a series they simply had to turn up for to win. But that would be wrong. Given where England started this tour, and the crisis that was beginning to engulf them, the three-one victory is a significant achievement.

When they arrived in South Africa, England were in a bad place. The two Tests in New Zealand in November had followed a script that had become depressingly familiar during previous winters. The batting underperformed, particularly in the opening Test, and the bowlers lacked a cutting edge across the board. It could have been a re-run of the tour to West Indies last winter. Or the one to Australia before that. Or the one to India before that. Same old, same old.

That series defeat against Kane Williamson's men meant England did not win a Test series in 2019 and confirmed the general stagnation that has been evident in the format for a while. Questions about Root's captaincy, and in particular the effect it was having on his batting returns, began to intensify.

Then, to compound matters, everything that could go wrong at the start of the tour to South Africa seemed to go wrong. Illness ravaged the squad in the opening weeks with a number of players either ruled out of the heavy first Test defeat at Centurion or struggling through it despite being ill. England did not want to make excuses after that defeat but there is no doubt the bug affected their performance. hen Rory Burns and Jofra Archer were injured before the second Test.

In those days between the defeat at Centurion and the game at Cape Town, the tour was at a tipping point. Things could have gone downhill, badly. It would have been a continuation of England's disastrous overseas displays of recent years and, frankly, that wouldn't have been much of a surprise. Instead, there was a remarkable turnaround over the next three matches.

This is just their second overseas victory in the last four years which is significant in itself but the fact they won the last three Tests by 189 runs, an innings and 53 runs and 191 runs respectively shows how dominant they were after Centurion. They went from down and out to playing like princes, despite James Anderson and Jack Leach heading home and Archer not playing another game.

Most importantly, perhaps, England have ended the series not just with a victory and 90 World Test Championship points but with a number of players who began the series on the fringes who ended it as more central figures.

Mark Wood and Ollie Pope are the two who have kicked on the most. Wood's nine wickets in Johannesburg was a reward for a fine display of aggressive, rapid bowling but perhaps more pleasing was the fact that he was able to back up with a similar display in Port Elizabeth. These were his first consecutive Tests since 2017. Given all Wood's injury problems, nothing can be taken for granted but if England can keep him fit, the dynamism and atmosphere he can generate could be a huge weapon.

Pope, just 22, finished the series with a Test average of more than 50 and a maiden Test hundred to his name. The general quality of his play and the level-headedness of how he approached his innings, most evident when he found himself with the tail in the first innings at Cape Town, stood out just as much as the runs he gathered. Pope has simply looked every inch the Test match batsman. Number six is the right place for him at this moment but it is clear he has the game and the temperament to bat higher.

There were others who advanced their causes too. Dom Sibley, another to register his maiden Test ton, occupied 784 deliveries across the four Tests which suggests he has the staying power and concentration required at the top of the order. He will have to improve, however, following three soft dismissals caught in leg-side traps. As county bowlers will know, playing off his legs is a strength of Sibley's but he will continue to be tested there and he will have to respond. Even so, an average of more than 50 for the series is a very good return.

Zak Crawley, another of England's young guns, improved with each Test he played, providing some impetus at the top of the order which suggested he deserves further opportunities albeit that he might have to tighten up some aspects of his play. Spinner Dom Bess was only called up as cover at the start of the tour and yet played important roles in the victories in Cape Town, where he created pressure for the seamers, and in Port Elizabeth, where he took five first innings wickets. A place on the tour to Sri Lanka is his likely reward.

Then there's Ben Stokes who averaged 45 with the bat, 22 with the ball and forced England over the line on the final, pivotal afternoon in Cape Town with a brilliant spell of bowling. A cricketer at the very top of his game.

There was a clear collective development too. England's game-plan seemed clear: the top three would try to occupy the crease and see off the new ball, the middle and lower order would try to punish tired bowlers and then the attack, with scoreboard pressure at their backs, could bowl aggressively and with variation. As head coach at Essex, Chris Silverwood gave the players a clear modus operandi. It seems he is doing the same with England.

Root has played his part too. His captaincy in the three victories was generally forward-thinking and proactive which it was not at Centurion. His decision to employ a short cover to Rassie van der Dussen on Monday (January 27), which the batsmen then chipped a simple catch too off Wood, was one example among a number. His batting looked in fine fettle for most of the series too and he managed to average 45 despite a highest score of 61. He might be a tad disappointed that he did not register a hundred but he won't be too despondent. This is the most significant victory of his captaincy so far.

It wasn't all sunshine and light. Joe Denly's form tailed off as the series wore on and a frustrating inability to convert starts into substantial scores continues to prevent him for nailing the number three spot. Jos Buttler had a difficult time with the bat, averaging less than 17, and was rusty at times with the gloves. Given England have won this series, both may get a stay of execution for the tour to Sri Lanka but they probably need a significant performance each on that tour to make the summer.

In general, however, this series has been a significant step forward. We have been here before of course. That was also the feeling after the tour to Sri Lanka at the end of 2018 when England swept to a three-nil series win over a similarly desperate side to the one South Africa have resembled at times in this series. There was talk after that Sri Lanka series that it was the start of something for that group of English players. It wasn't.

Let's be clear. Three victories do not suddenly make England world-beaters. The batting has improved but consistent first innings totals in a variety of conditions are the standard against which they will be judged. A conversion rate of three hundreds and nine fifties needs work too. The wicket-keeping situation is still not resolved and despite Bess's strong showings on this trip, England's spin bowling stocks cannot yet be described as strong. Nor have the structural deficiencies at the county level, including scheduling and the quality of pitches, miraculously been solved.

But none of that, nor the struggles of South Africa, should diminish what has been an excellent series victory, achieved away from home and having begun the tour in a state of flux. It has been quite some turnaround since Centurion.

Is this one of England's best overseas victories? No. Is it still a very fine achievement anyway? Yes. Given where they started, that will do England very nicely indeed.