"The skipper was absolutely magnificent right throughout the series," McCullum said. "Not just on the field, where everyone sees the decisions he makes and the strings he pulls, but it's his man-management and his ability to get the very best out of each member of the side, off the field, which is the most impressive part from our point of view.

"It's the captain's mantra, this side is very much in the image of the skipper," McCullum added. "And Stokesy wants the guys to go out there and play with the most amount of freedom that they can.

"He's got the benefit of a long and distinguished career behind him, and he's in that stage of his life where he wants to do something significant and make a real impact, not just on the game but on other people's careers. He's identified that taking away that pressure and that fear of failure allows the talent and the skill to come out."

Stokes himself was at the crease on the final day, finishing 35 not out in England's pursuit of 167 for their clean sweep. But it was England's efforts on the very first day of the tour, in Rawalpindi, that set the team on course for history, as they racked up a remarkable 506 for 4 in 75 overs, including four centuries from Zak Crawley, Ben Duckett, Ollie Pope and Harry Brook, the eventual Player of the Series.

"That was more than I thought we were going to make, to be honest," McCullum said. "The way that Crawley and Duckett started for us in that Test match, it really laid a marker out for where this team wants to be, and for how brave our cricket needs to be as well.

"It was about playing the role that the team needs you to play, rather than getting too caught up in your own stuff, and it was a huge day that allowed us to try and force a result. Maybe the series would have been different if we hadn't have gone down that route."

The defining aspect of England's wins, however, was ultimately their ability to prise out 20 wickets in a Test, with a range of different tactics and personnel coming to the fore, from the part-time spin of Will Jacks and the skilful use of reverse swing in Rawalpindi, to Jack Leach's first-innings four-for and the decisive pace onslaught of Mark Wood in Multan, and ultimately to the remarkable emergence of the legspinner Rehan Ahmed with his debut five-for in Karachi.

"It's a great achievement," McCullum said. "If you look at the whole six or seven months, we've taken 20 wickets in a Test on nine out of 10 occasions. So it's one thing scoring fast and putting teams under pressure with the bat, but you got to be able to bowl teams out as well.

"And the mantra within the group is 'how do we take wickets?' Every time we've got the ball in our hand, 'how are we going to try and get this guy out?' If you go for runs, you go for runs, but we back ourselves that will chase those runs down later on. I think once you have that mindset, you free yourself up from having to worry about runs. It allows you to look at things with a positive mantra."

Stokes' field placings were eye-catching throughout the tour, but they had to be too, with not a single traditional slip catch off the seamers all series long. Instead, he backed his bowlers with leg slips for the short ball into the ribs, and close catchers in the eyeline to capitalise on mistimed drives, a process that Stokes himself admitted had been entirely down to instinct, rather than pre-set plans.

"A lot of my decisions were based on what I thought was the best option at any given time," Stokes told Sky Sports. "I feel as if out here is probably the easiest conditions to mess around with a few different things. You don't have to have a slip because it's not going to go to slip in three games for us. So you use that slip somewhere else, maybe to visually upset the batsman."

Watching on from the dressing-room, McCullum was impressed. "The skipper never lets the game drift," he said. "He's always got something happening. He's always pulling a string somewhere and the guys follow him. It's a great combination to have, and it makes it pretty easy when you're watching from up in the coach's box.

"There's maverick in it and genius in a lot of it," he added. "He's just got an insatiable appetite to keep moving the game forward, which is super-impressive. But for me, it's the man management, it's the consistency of message, it's the pure passion and drive that he's got to make a significant difference in Test cricket, and English cricket, which is most impressive.

"So I feel incredibly lucky that I've taken over this job when Stokesy has got the reins, and I think he's only going to get better and better and better, which is quite scary. Because if he continues to improve and drive this team forward then, with the talent that sits within the dressing room, they will give it a good shake anyway.

"I don't do bugger all, to be honest," McCullum joked. "I just make sure that the guys remain consistent with their own beliefs, and that they all want to be the best version of themselves. To be honest, it's a really easy job … don't tell my bosses. But I'm really enjoying myself, and I couldn't I couldn't have asked for a better opportunity."

Looking on from the Sky Sports studio, however, Stuart Broad gave a more nuanced assessment of McCullum's under-stated influence in the dressing-room.

"I've not seen him throw many balls, I've not seen him talk technically to anybody, but you watch every training session, he walks around and speaks to every single player," Broad said. "Just checking in and seeing how they are, seeing what their mindset's like, making sure they are taking the options that are right for the mantra of the team. He's an incredible man-manager."