Manchester United's five years of failure examined: How and why the trophies stopped and key factors explored

"The last piece of the puzzle." That is how Jose Mourinho described Manchester United's Europa League final win over Ajax in May 2017. United were, he pointed out, now a club that had won every trophy in the world of football.

The victory that night in Stockholm was supposed to be the beginning, not the end. It may have been their third trophy of the season - as Mourinho memorably gesticulated with his fingers - but it had also been what he described as his most difficult season as a manager.

United muddled through at times, finishing sixth in the Premier League. But back then even a spluttering version of the red machine seemed capable of churning out silverware. Louis van Gaal had been sacked with the FA Cup plonked right in front of him.

There was an acceptance that United needed to improve and an assumption that they would. Instead, the fifth anniversary of that win came and went but it remains the club's most recent trophy. Liverpool have won six since then. Manchester City have won 11.

How has that happened? How has it been allowed to happen? It is a tale of hubris and self-harm, a club hindered by too many voices and too few. From ownership to recruitment, the problems were myriad. The solution? It is unclear whether that has yet been found.