England head to the World Cup in India aiming to become just the third team to retain their title and seeking to underline their status as the pre-eminent force in white-ball cricket.

As recently as 2015, England suffered a humiliating group-stage exit but they are now the reigning world champions in both men's one-day international and Twenty20 cricket.

Test cricket, particularly Ashes series against Australia, has long been regarded as the pinnacle for England players.

But a 15-run defeat by Bangladesh in Adelaide that knocked England out of the 2015 World Cup prompted a rethink.

Andrew Strauss, who took over as managing director of England cricket after the debacle, encouraged greater separation between the Test and limited-overs teams.

The former Ashes-winning captain sacked Peter Moores as coach and appointed Trevor Bayliss, primarily for his white-ball knowledge.

Significantly, Eoin Morgan was retained as limited-overs captain.

There was also greater continuity of selection.

Team analyst Nathan Leamon, quoted in "White Hot: The Inside Story of England Cricket's Double World Champions", said the focus was on the long-term.

"We suddenly stopped selecting for the next series and started selecting for the World Cup in four years' time," he said.

"They were asking, 'Is this player still going to be there? Does he play the way we want to play?' If not, they were nowhere near the squad."

England boosted their ODI schedule, with leg-spinner Adil Rashid, a key bowler in Morgan's line-up, playing 83 50-over matches between the 2015 and 2019 editions.

Using the knowledge gained from his time playing in the Indian Premier League and following the example of the New Zealand side who had hammered England at the 2015 World Cup on the way to the final, Morgan insisted on an aggressive batting approach.

- 'Positive mindset' -
The results were dramatic.

In their first series after the 2015 World Cup England posted their first 400-plus total during a five-match series against New Zealand that they won 3-2.

Boasting a batting line-up including Jonny Bairstow and current skipper Jos Buttler, they lifted the world record for an ODI total to 444 in 2016, 481 in 2018 and 498, against the Netherlands, last year.

With such batting power, England's bowlers were encouraged to attack, rather than worry too much about restricting the run-rate.

Pace greats James Anderson and Stuart Broad became Test specialists while Chris Woakes and Liam Plunkett were identified as key one-day bowlers.

Morgan was also prepared to be ruthless, jettisoning ODI regular David Willey on the eve of the 2019 World Cup to bring the newly qualified Jofra Archer into the squad -- a move vindicated by the express quick's performances.

Even then, with all their meticulous planning and the form of multi-format stars such as Joe Root and Ben Stokes, England still needed a Super Over to finally see off New Zealand in a thrilling World Cup final at Lord's for the country's first triumph in tournament history.

Four years on, can they retain their title in India?

England, bidding to equal the West Indies and Australia by winning consecutive World Cups, have played only about half the number of ODIs in the four years since the 2019 edition compared with the previous four-year cycle as Tests and T20s became the focus of attention again.

Due in part to franchise commitments around the globe, they have not always fielded a full-strength side.

"It's been very different since 2019, for a number of reasons," Root told author Matt Roller earlier this year, while at the IPL with Rajasthan Royals.

"The 50-over game has suffered the most -- that has been the format where you haven't consistently got the best teams being put out."

But the fact the bulk of the squad have played in the IPL means Ahmedabad, where England begin their World Cup campaign against New Zealand on October 5, will be a familiar venue.

Harry Brook, at 24, is the only specialist England batsman under 30 but Buttler told The Times last month: "If people are still performing, age is irrelevant."