For some time it has been a case of when rather than if Burnley would be promoted from the Championship.

Vincent Kompany came in last summer with the club short on confidence having been relegated from the Premier League and with a large amount of debt.

But the former Manchester City captain has transformed the Clarets into the most dominant side in the second tier.

After their win over Middlesbrough returned them to the big time, BBC Sport takes a look at how they did it.

Kompany responsible for a transformation at Burnley

Kompany, 36, returned to English football following two years in charge of Belgian side Anderlecht before leaving by mutual consent at the end of last season.

His arrival at Turf Moor raised some eyebrows, given his time in England as a player with City was confined to the Premier League. But the appointment showed that Burnley meant business.

The club had been relegated from the top flight after a miserable season and their drop to the second tier coincided with having to pay off a "significant proportion" of a £65m loan from American finance company MSD Holdings.

The sales of several senior players helped towards that, with England goalkeeper Nick Pope moving to Newcastle, defender Nathan Collins joining Wolves and winger Dwight McNeill being sold to Everton. Long-serving defenders Ben Mee and James Tarkowski also left on free transfers to join Brentford and Everton respectively.

In came a number of players from Belgium, including midfielder Josh Cullen from Anderlecht and winger Anass Zaroury from Charleroi.

Burnley also turned to the loan market to bring in forward Nathan Tella from Southampton and Chelsea full-back Ian Maatsen, while Kompany utilised his Manchester City contacts to recruit goalkeeper Ari Muric and defender Taylor Harwood-Bellis.

It says a lot, however, that the way in which Kompany has led the side has meant that their financial troubles have been completely overshadowed.

What could have been another forgettable campaign has proved quite the opposite, although Kompany did need some time to pick up some momentum.

Having beaten Huddersfield in the opening game of the season, Burnley drew three and lost one of their next four games, including letting a 3-1 lead slip against Lancashire rivals Blackpool in a feisty encounter at Turf Moor.

Having overhauled previous boss Sean Dyche's squad into his own image, Kompany's side grew stronger and have so far been beaten just once more in the league all season.

"They have been unbelievable this season," former Burnley winger Glen Little, who is part of BBC Lancashire's commentary team, said.

"So much has changed from the Dyche squad of last year, with Kompany introducing more than 20 players, from a range of countries that they'd never been shopping in before.

"The impact that some of them have made has been almost instant, and astute loan signings like top scorer Tella from Southampton have also helped.

"The club really has been transformed with the changes that Kompany has made and the style of play that he has introduced. Neutrals are now commenting just how good it is to watch Burnley play.

"They've lost only twice all season, they've scored more and conceded less than any other team in the Championship and the aim now will be to add to the young squad they have, to make sure that they return to the top flight and stay there."

'You don't expect to see Burnley back in the championship anytime soon

Burnley's sensational form has seen them build a magnificent 19-game unbeaten run in the league, with their most recent Championship defeat coming against fellow promotion chasers Sheffield United in early November.

They have continued their domineering momentum ever since and continued where they left off following the World Cup break.

"Burnley's promotion back to the Premier League has looked a certainty since they returned from the World Cup break with nine straight wins in the Championship," BBC Radio Lancashire's sports editor Andy Bayes said.

"They've done it with style and swagger, with goals aplenty and entertainment pretty much guaranteed.

"The Clarets weren't always easy on the eye under Sean Dyche but they regularly met their target of maintaining their top-flight status.

"The change in style under Vincent Kompany has been obvious from day one. Fast-flowing football and playing out from the back have been the staple diet.

"He's been backed in the transfer market and introduced a number of players, who, perhaps weren't household names before their arrivals. It'll be intriguing to see how the likes of Manuel Benson, Zaroury and Cullen perform at the highest level next term."

Despite dipping into the transfer market, Kompany kept a core of senior players and ensured they could all work together.

The strategy paid dividends as the club head towards being the first team since Newcastle United's 2009-10 squad to go through an entire Championship season unbeaten at home on the way to sealing the second-tier title.

"It has not all been new faces that have revelled under Kompany's coaching," Bayes added. "Charlie Taylor, a left-back by trade, has played largely as a centre-back, Jay Rodriguez and Ashley Barnes have both led the line well, with Josh Brownhill and Jack Cork patrolling the midfield.

"Loan signings have proved important too. Harwood-Bellis, Maatsen and Tella are three examples who look ready to step up.

"Naturally next season will be a far tougher challenge for Kompany and his team. Both the manager and the players are rightly gaining plaudits.

"For a squad that's gone under enormous change, they've done incredibly well to make what's looked light work of the Championship - and you wouldn't expect to see them back anytime soon."