Manchester City beat Chelsea 4-3 on penalties to win the Carabao Cup in February
Manchester City return to Premier League action on Saturday knowing they are 15 games away from winning an unprecedented quadruple.
With the League Cup already under their belt, they are two points behind leaders Liverpool in the league with a game in hand, and will face Brighton in the FA Cup semi-finals and Tottenham in the Champions League quarter-finals.
What's more, they are the bookies' favourite to win every competition. So can they do it?
Has anyone come this close before? Manchester United's Treble-winning season in 1998-99 is widely regarded as the greatest achievement in English football
Only two other English teams have still had the chance of winning the quadruple by 30 March: Chelsea in 2006-07, and Manchester United in 2008-09.
Managed by Jose Mourinho, Chelsea lasted until 1 May with their hopes of a clean sweep alive, before losing to Liverpool on penalties in the Champions League semi-finals.
Two years later, Sir Alex Ferguson's Manchester United side made it to 19 April before their dream ended with a penalty shootout defeat by Everton in the FA Cup semi-finals.
That United team got to within three matches of winning all four trophies, also losing to Barcelona in the Champions League final.
The best haul in United's history famously saw them win the Treble in 1998-99 but they were nowhere near the quadruple that season, losing to Tottenham in the quarter-finals of the League Cup on 2 December.
Another legendary Premier League side, Arsenal's 'Invincibles' of 2003-04, might have stayed unbeaten for the duration of their league campaign but their quadruple hopes ended on 3 February when they lost 3-1 on aggregate to Middlesbrough in the League Cup semi-finals.
Manchester City's 'Centurions', who broke a series of Premier League points and scoring records on their way to last season's title, were fighting on four fronts until 19 February before losing to Wigan in the FA Cup.
But City's best effort before this year actually came in 2013-14, when Manuel Pellegrini's side lost in the FA Cup quarter-finals on 9 March - again going out to Wigan, so it is probably a relief they do not have to face the Latics this season.
The closest English teams have come to winning the quadruple (Manchester City this season based on results so far)SeasonTeamPremier LeagueFA CupLeague CupChampions LeagueDate2006-07Chelsea2ndWinnersWinnersSemi-finalists1 May2008-09Manchester UnitedWinnersSemi-finalistsWinnersFinalists19 April2018-19Manchester City? (currently 2nd)? (currently semi-finalists)Winners? (currently last eight)6 April (at least)2013-14Manchester CityWinnersQuarter-finalistsWinnersLast 169 March1978-79Nottingham Forest2ndFifth roundWinnersWinners26 February
Teams have had the chance of a quadruple since the League Cup was established in 1960, but the leading clubs did not always enter or take it seriously until entry was made compulsory in 1971.
Before the Premier League and Champions League era began in 1992, Brian Clough's Nottingham Forest went closest in 1978-79 when they got to 26 February before losing to Arsenal in the FA Cup fifth round.
While runners-up were allowed to compete in the Champions League from 1997-98, only the league champions or the holders entered the European Cup, limiting quadruple opportunities - as did the ban excluding English clubs from Europe between 1985 and 1990.
Liverpool's all-conquering side of the late 1970s and early 1980s had nine successive seasons in the European Cup between 1976-77 and 1984-85, and completed a Treble of league, European Cup and League Cup in 1983-84.
But they went out of the FA Cup in the fourth round that year, on 29 January - which means that, in terms of games, they were five matches short.
Date-wise the closest the Reds came to a clean sweep was in 1982-83, when they got to 20 February before losing to Brighton in the FA Cup fifth round. That season they won the league and the League Cup, but lost in the quarter-finals of the European Cup.
Of course, there have also been teams who have challenged for pretty much everything and ended with nothing. Leeds went out of the League Cup in the third round in 1969-70 but went close in the league, FA Cup and European Cup - before finishing second and losing in the final and the semi-final.
Has anyone done it elsewhere in Europe?
Pep Guardiola won six trophies in the calendar year of 2009 with Barcelona - the Champions League, La Liga, Spanish Cup, Fifa Club World Cup, Uefa Super Cup and the Copa del Rey.
But he failed to win the 'proper' quadruple during his best season with Barcelona in 2009-10. They picked up the Spanish Cup and La Liga - showing Barcelona's dominance in Spain - but fell short in the semi-finals of the Champions League.
They added the Uefa Super Cup and the Club World Cup instead and repeated the feat in 2015-16.
Real Madrid arguably went one better, replacing the Copa del Rey with the Champions League as part of their four-trophy haul a year later.
They won four trophies again in 2017-18 but finished a mighty 17 points below Barcelona in La Liga and were also knocked out in the quarter-finals of the Copa del Rey.
ClubSeasonTrophies wonReal Madrid2017-18Supercopa de Espana, Super Cup, Club World Cup, Champions LeagueParis St-Germain2014-15, 2015-16, 2017-18Trophee des Champions, Ligue 1, Coupe de France, Coupe de la LigueReal Madrid2016-17Super Cup, Club World Cup, La Liga, Champions LeagueBarcelona2015-16Super Cup, Club World Cup, La Liga, Copa del ReyBayern Munich2012-13DFL-Supercup, Bundesliga, DFB-Pokal, Champions LeagueCeltic1966-67European Cup, Scottish First Division, Scottish Cup, Scottish League Cup
Interestingly, Paris St-Germain won all the silverware in France in 2014-15, 2015-16 and 2017-18 - picking up the Trophee des Champions, Ligue 1, Coupe de France and the Coupe de la Ligue.
But they were not able to extend their dominance to Europe and were knocked out in two quarter-finals before Real Madrid ended their journey in the last 16 of the Champions League in 2018.
The season before Guardiola took over at Bayern Munich was a successful one. The German giants won every competition they entered, lifting the Champions League and the Bundesliga as well as the German Cup and the German Super Cup (the equivalent of the Community Shield).
Celtic are arguably the only team to have won the ultimate quadruple of domestic trophy, European Cup and both domestic league cups. They picked up the First Division, European Cup, Scottish Cup and the Scottish League Cup in 1967. The Hoops are also currently chasing an unprecedented Treble-Treble.
Pep Guardiola has won four trophies with Manchester City, including the Community Shield, two League Cups and a Premier League titleWhat have Man City done to get here?
City may not be matching their Premier League dominance from this time last season, when they had seven more points and were 16 points clear at the top, but their progress in the other three competitions has been almost flawless.
They have had 16 wins from 18 domestic cup or European games in 2018-19, eight of them by a three-goal margin or more, but because they have not met many big names along the way there is an argument that they have had it easy.
Ex-Chelsea striker Chris Sutton told BBC Radio 5 Live: "You can't say the draws have been rigged but they have had an unbelievable run in the Champions League, the League Cup and the FA Cup. They have hardly played a decent side, with respect."
Manchester City's opponents in cup competitions this seasonCompetitionOpponentsStage reachedFA CupRotherham United, Burnley, Newport County, Swansea City, Brighton & Hove AlbionSemi-finals (at least)League CupOxford United, Fulham, Leicester City, Burton Albion, ChelseaWinnersChampions LeagueHoffenheim, Shakhtar Donetsk, Lyon, Schalke, TottenhamQuarter-finals (at least)
Domestically, the view that City have got lucky appears to stack up - on their way to winning the Carabao Cup they won against a much-changed Leicester, who beat them in the league less than two weeks later, but the only team they met from the top half of the Premier League was Chelsea in the final.
In comparison, Chelsea had to get past Liverpool - albeit a shadow Reds side that had rested most of their big names - and Tottenham on their way to Wembley.
Manchester City beat Premier League sides Leicester and Chelsea in penalty shootouts on their way to victory in the League Cup
City's FA Cup draw has been even kinder, featuring only one top-flight opponent so far. But that has undoubtedly been helped by the attitude of many Premier League clubs, including title rivals Liverpool as a prime example, not to prioritise the tournament.
While City have played a strong team in every tie, regardless of the opposition, Reds boss Jurgen Klopp rotated his squad in their third-round defeat at Wolves, making nine changes. He was not the only manager to do so, and that is part of the reason why only seven out of 20 top-flight teams made it to the fifth round, where City played League Two side Newport in the last 16, with seven teams going out to lower division teams.
Semi-finalistsAverage league position of opponentsOpponents faced on route to the semi-finalsManchester City47Rotherham, Burnley, Newport, SwanseaWatford47Woking, Newcastle, QPR, Crystal PalaceBrighton26Bournemouth, West Brom, Derby, MillwallWolves24Liverpool, Shrewsbury, Bristol City, Manchester United
But while there has been an element of fortune in who City have played - or avoided - in the domestic cups, it has played a much smaller role in deciding who they have met so far in Europe: Lyon, Shakhtar Donetsk, Hoffenheim and Schalke.
Former Arsenal striker Ian Wright told BBC Radio 5 Live: "If you were City and you were able to pick your way through a cup competition, you would probably have picked that!"
But, quite simply, they earned the right to play so-called weaker opposition, firstly by winning the Premier League last season and then by winning their Champions League group.
The former ensured they were in the top pot of seeds for the group stage and avoided all the other giants, unlike Liverpool who were in pot three and got Paris St-Germain, Manchester United (pot two, Juventus) or Tottenham (pot two, Barcelona).
Even so, City were not handed the best draw on paper of any of the top seeds - their opponents in Group F might have lacked glamour but they still had an average Uefa co-efficient ranking of 46 based on their results in European football over the past five seasons. Using the same criteria as Uefa, three of the eight top seeds - PSG, Bayern Munich and Barca - had easier draws than City.
Similarly, winning their group was the key to City getting a favourable draw in the last 16, because again it meant they avoided the big names. True, Schalke (seeded 24th) were the third-lowest ranked side left in the tournament, but along with Atletico Madrid (2nd), Roma (21st) and Ajax (31st) they were one of only four possible opponents for City because the other English clubs all finished as runners-up in their groups.
Ajax were the weakest team left in the last 16 on paper, but just ask Real Madrid how that "easy" draw turned out.
How many games would City play in total?
City have already played 48 games this season, excluding their Community Shield victory over Chelsea. They will need to play 63 in total to win all four competitions.
The most games any English team has played was 71, by Stoke City in 1972. More recently, Chelsea played 69 games as they dropped down from the Champions League to win the Europa League in 2012-13. They also reached the FA Cup and League Cup semi-finals but only finished third in the Premier League.
Guardiola's side have relied on their squad depth this season - using 30 players in total, only three fewer than Arsenal, who have used the most out of the other Premier League teams.
Defender Kyle Walker has played the most minutes (3,288) by an outfield player for City, while four others - Aymeric Laporte, Bernardo Silva, Raheem Sterling and Fernandinho have also clocked over 3,000 minutes each.
But there's been no sign of City slowing down. They have scored 142 goals already and average 2.9 per game.
Will they do it?
City midfielder Kevin de Bruyne said it would be "nearly impossible" to win the quadruple, while Guardiola said it was "incredible" that City are even fighting for all four titles.
They will need some good fortune if they are going to do it, but an element of "top-team luck" seems to be on their side already - they were fortunate to receive a contentious penalty and an apparent offside goal against Swansea in their FA Cup quarter-final victory.
That on its own will not be enough, however, especially during a tough run of fixtures in April, including an 11-day period where they face Tottenham three times in two competitions.
They hold a slight advantage in the title race but their game in hand that could see them leapfrog Liverpool at the top of the Premier League is at the home of neighbours and bitter rivals United, who have been rejuvenated under Ole Gunnar Solskjaer.
"I just don't think it will be that easy for Manchester City to play a good Premier League team three times in a short space of time," former Republic of Ireland captain Andy Townsend told BBC Radio 5 Live.
"Even though the first one against Spurs is a Champions League tie, it is massive for the bigger picture if Spurs can turn City over. Knowing there are two more games against Tottenham before going to Manchester United is a tough, tough spell to go through."
Riyad Mahrez scored the winning goal for Manchester City as they beat Tottenham 1-0 in the Premier League in October
City have won their past three meetings with Tottenham. But Spurs boss Mauricio Pochettino has a pretty good record against City, winning four and drawing two in his 12 games against them.
Potential Champions League semi-final opponents Ajax and Juventus also have history on their side. The Blues have won only one in six against Juve and have never beaten Ajax.
City won't want to meet Barcelona in the final either. They have lost five of their past six meetings, scoring just five goals and conceding 12. City have also failed to win a game in Madrid - the venue for the final.
If Liverpool get there, they will fancy themselves to beat City. Klopp's side were the ones to knock them out in last season's quarter-finals and have lost only once in their past five meetings.
And ex-Arsenal striker Wright told BBC Radio 5 Live he thinks Liverpool will win the Premier League.
"I think Manchester City will win the Champions League and the FA Cup but I can see Liverpool winning the Premier League," he said. "What City are trying to achieve, what they did last season and what they are doing this year, is unbelievable."
Simon Gleave, head of analysis at Gracenote, says it is statistically unlikely that City will win all four competitions.
"Our Euro Club Index estimates the chance of City winning the quadruple at around 9%," he said. "They have a 59% chance of winning the Premier League, a 79% chance of winning the FA Cup and a 20% chance of winning the Champions League."
One thing is for certain - if City win their next 15 games, they will achieve a quite remarkable feat.
And while that may seem like a huge ask, they have done it before, winning 20 consecutive matches last season.