If ever you need reminding of the fickle nature of football success, cast your mind back to May 1999 and a rather gloomy afternoon beneath the old twin towers of Wembley Stadium.

Gillingham Football Club were facing Manchester City in front of 77,000 frenzied fans in the play-off final. At stake was a place in the Championship - or Division One as it was known back then.

For the Gills it offered the tantalising possibility of a second promotion in three years - a remarkable achievement just four years after slumping into administration and facing expulsion from the Football League.

For City, it was the chance for a swift return after they found themselves in the third tier for the first time in their history.

With nine minutes to go, the game was on a knife-edge at 0-0. But a lovely flowing move saw Gills' frontman Carl Asaba toe-poke a goal which sent the travelling Medway fans into raptures. A little over five minutes later, Asaba's cheeky back heel sent his strike partner Robert Taylor clean through. A stunning finish and the Gills were two-nil with just three minutes to play. The Gills - and most of Kent - were in ecstasy. Surely they would reach a height the club had never before achieved?

But then fate intervened, as any long-suffering football fan will tell you happens with such crushing inevitability.

As the final minute of the 90 started ticking down, City grabbed one back. In the fifth minute of added-time, as the Gills fans urged the referee to blow the final whistle, City's Paul Dickov scored a remarkable equaliser.

Extra-time gave way to penalties and three-missed kicks later the Gills were travelling back along the M2 wondering just how they'd managed to snatch defeat from the jaws of victory.

Fast forward 23 years and the path of the two clubs could not be more different.

Man City are, today, one of the wealthiest clubs in the world. They play their games in the modern, 53,400-seater City of Manchester Stadium. Their squad is full of household names and, since that day in 1999, they have won the Premier League five times. They currently sit a point clear at the top with hopes high of a sixth title. Tonight (TUESDAY) they face Real Madrid in the first leg of the Champions League semi-final.

For the Gills, in their historic 11,000-capacity Priestfield home, it's a very different picture.

They begin this season in the bottom tier of English league football having been relegated last season.

Having started the season with a disappointing loss away at Wimbledon but beat Rochdale this weekend before long-time chairman Paul Scally announced he was taking "extended leave".

Currently with one foot in the relegation zone of League One, only a win on Saturday and results elsewhere going their way, will ensure they don't swing their other leg over and disappear through the trapdoor into League Two.

While City fans will be keeping an eye on the other Champions League semi-final this week, the Gills will be tonight praying Fleetwood Town lose at home to Sheffield Wednesday to give them more of a fighting chance or survival.

It's probably, in truth, an unfair comparison.

City had a long, successful legacy and enormous fan base upon which to build their return to glory. Not to mention the arrival, in 2008, of new owners from cash-rich Abu Dhabi which propelled them into the world's elite.

Gillingham have, since then, continued to be controlled by a south London businessman who made his money from the slightly less glamorous world of photocopiers.

While Paul Scally is a Marmite figure for many Gillingham fans, one thing needs saying from the outset; and that is that not only did he save the club from potential demise, but has also been at the helm during the most successful period in its more than 100 year history. Relegation this weekend or not.

Few will forget the club's remarkable turnaround after he took control - elevating them from the bottom of what is now League Two and, eventually into what is now the Championship (they bounced back after that defeat by City the year after, beating Wigan Athletic in the play-off final in another thriller - this time emerging victorious 3-2 after extra time).

Those days in the Championship - reaching an all-time high of 11th in their first season in the division - allowed even the most cynical fan to start dreaming that perhaps, just perhaps, Scally's repeated claims that the team could reach the Premier League could be more than just a pipe-dream.

But just why are there now plenty of young fans for whom those glory days are simply pages in the history books rather than providing the platform to future success so many of us felt the club was once capable of?

Of course, it's easy to look at one man - the one constant at the club over the last 25 years: Paul Scally.

The chairman is certainly a prickly creature even at the best of times. He has controlled the club with little time for critics of his style or decisions. He has waged war with anyone who he believes has crossed him or the club - be that rival clubs (he used to regularly criticise Charlton Athletic when the south London club was in the Premier League for trying to convert Kent fans to The Valley rather than Priestfield), the local media (his use of banning powers is legendary), or indeed fans who have suggested perhaps it's time for a new face at the helm.

Yet he has kept the wolf from the door of a club in a sport where the distribution of monies has been so skewed towards those at the very top.

Gillingham have not crashed to the ground like Bury. It has not fallen into the National League. Its stadium, while not quite the Theatre of Dreams, is (assuming you're not an away fan forced to sit in the uncovered end on a chilly or wet winter's day), presentable.

Yet when has a football fan ever been satisfied simply with not going bust?

The truth is that Scally has become Gillingham and perhaps a victim of the success the club experienced in those first heady days under his control. A failing of the club in any regard he takes as a personal slight and he remains convinced he is the man to not only steady the ship but to sail it, eventually, into more successful waters. When fans criticise him he feels obliged to respond - speaking of the emotional turmoil it causes him - rather than just keeping an often more dignified silence.

Certainly his reputation now comfortably proceeds him in footballing circles. He is one of the longest serving chairman in the English game.

Managers have come and gone - usually with Scally showing remarkable patience, in footballing circles, when it comes to allowing them the opportunity to turn things around once the rot sets in. But, like a relationship, if the break-up is acrimonious, Scally does not hold back in his show of public anger.

Speaking of comments made by former boss Steve Evans in his last few months at the club (he was booted out midway through this season with the club looking almost relegation certainties) - Scally said: "It was a vicious downward spiral of negativity, anger, frustration and in certain instances pure hate. It was hugely ugly, nasty, unnecessary and damaging to our club."

But aside from the occasional cup run, the club's stature in the game has failed to build on its hey-day some 20 years ago.

Is its realistic future now simply as a yo-yo club between the professional game's lowest divisions? Quite possibly.

And that has left many fans frustrated - and more than a few to dare face Scally's wrath by suggesting he make way for a new face (and one, the assumption goes, with deeper pockets). Those who funded a plane to fly over Priestfield in October pulling a banner reading 'Time for change - Scally out' may, or may not, speak for the majority, but the fact it happened suggests all remains far from well, despite the positive progress the club has made under new boss Neil Harris.

Faced with every call for Scally's departure, his remarks have been along the same lines: "If someone will look after the club and grow it then I'm happy to sell it." Quickly followed by the inevitable: "But no one has come calling."

Over the years fans have heard plenty of talk of "credible investors" or potential suitors to take the club over. None of which have ever materialised.

In addition, throughout his tenure, he's talked of building a new state-of-the-art stadium. Plans have been drawn up, campaigns started. But the club show little signs of shifting from Priestfield - a ground, it should be said, which has been dramatically improved and updated during Scally's period in charge.

He has said without such a venue, the club's success on the pitch will always be hamstrung.

He is, of course, quite right. A venue with 365-days-a-year revenue generating potential would result in money flowing into the club which could then be used to bolster the squad. He is, instead, pushing ahead with plans to make the most of Priestfield's potential, with the club now hosting everything from weddings to music concerts.

The reality, in this day and age, is that for a club to emerge as wheat from the chaff it needs money behind it. And a lot of it.

The biggest question fans may need to ask themselves - should results not go their way at the weekend - is whether, when it comes to Paul Scally - who, objectively, may rub people up the wrong way but remains committed to the club's long-term success - it's a case of "better the devil you know".