London - England crushed South Africa by 191 runs on Monday to clinch a 3-1 Test series victory over the hosts in Johannesburg.
We look at three things we learned from England's impressive success against the Proteas:
England's pace attack given fresh impetus
With James Anderson, 37, and Stuart Broad, 33, in the twilight of their careers as the spearheads of England's pace attack, the South Africa tour provided welcome reassurance that the fast bowling cupboard will not be bare when they eventually step down.
Mark Wood made an eye-catching return to Test cricket after an 11-month absence, with 12 wickets in two matches to help fill the gap left by the injured Anderson.
Wood impressed in the fourth Test as England broke South Africa's second-innings resistance, taking 4-54 to complete match figures of 9-100 and earn man-of-the-match honours.
The 30-year-old was grateful for the chance to play after being unsure whether he would be selected an hour before the start of the fourth Test following a short turnaround from the third match in Port Elizabeth, with England looking to carefully manage his return to the international arena.
"There was a bit of doubt going into the game but boy am I glad I played now. I'm over the moon," Wood said.
"I've had a lot of dark days but everybody's been pretty supportive."
After a tough tour of New Zealand, where on flat, slow pitches he took just two wickets in as many Tests and was also racially abused by a spectator in Mount Maunganui, Jofra Archer's involvement in South Africa was limited to one Test by an elbow injury.
But that match, the first of the series at Centurion, saw Archer take six wickets, including 5-102 in the second innings, to show why England fast-tracked the 24-year-old into the team in time for their World Cup triumph last year.
England all-rounder Ben Stokes, who impressed with the bat, also chipped in with 10 wickets and was named man of the series.
Buttler's Test future in doubt
Jos Buttler is one of the most dynamic batsmen in one-day cricket but he has endured a miserable time with the bat since resuming wicket-keeping duties in the Test arena and appears in danger of losing his place.
Since he took over from Jonny Bairstow at the start of England's winter, Buttler's average in five Tests against New Zealand and South Africa is below 20.
Buttler was a key figure in England's thrilling World Cup-winning campaign in the 50-over format last year, but he has looked fatigued and confused since, unable to transfer his form to the longer format of the game.
There are mounting calls to bring Ben Foakes back into the fold in Buttler's place.
The Surrey wicketkeeper was man of the series the last time England went to Sri Lanka in late 2018 and they head back there in March.
England's top order buckles down at last
When Rory Burns was forced to leave the tour with an ankle ligament injury suffered while playing football on the eve of the second Test, England's top order looked in disarray.
Dom Sibley had a Test average of 14.20 and Zak Crawley had one Test run to his name, while Burns, who will miss England's tour of Sri Lanka in March, was averaging more than 55 in Test cricket during England's current winter.
But Sibley and Crawley rose to the challenge, with Sibley recording a maiden century in Cape Town.
In Johannesburg, the pair recorded England's first century opening stand since December 2016.
At 22 years and 15 days, Ollie Pope's unbeaten 135 in the third Test meant he became the youngest man to score a century for England since Alastair Cook in 2006.
And with captain Joe Root looking assured at the crease, there are plenty of reasons for England to look to the future with optimism.
"The sky's the limit for us. We're at the start of something," Root said.