He took over in the autumn of 1996 when the North London side was in a bit of a rut.
They long had the tag of 'boring, boring Arsenal' but the back end of George Graham's reign and Bruce Rioch's solitary season in charge ensured that the chant '1-0 to the Ar-sen-al' had lost its self-mocking irony.
Namely because they were no longer going 1-0 up and defending such a lead with their lives.
Wenger arrived and injected not only a new style of play but also a different off-field culture that many, if not all clubs in Britain, follow today.
The style was changed to a fluent attacking one which saw 1-0 to the Arsenal replaced with three or four nil while the player diet of steak, chips and beer was replaced with pasta, fruit and mineral water.
It certainly gave Arsenal an extra lift in their step and made them serial title contenders - which they won three times - and also reached two European finals.
However, the spark can only fizzle so long before it burns out and that time has come.
Arsenal, while still making the top four and are regular entrants in the European Cup, appear to have gone stale and so to has their manager.
Every time when Manchester United looked like doing this, Alex Ferguson would somehow manage to make the necessary tweaks to his team and his gameplan to ensure that they could bounce back.
Wenger however seems to be stuck in a rut and shows no sign of restoring the joie de vivre that made Arsenal successful and brought them many admirers.
So a change maybe necessary to see if someone else can give the club the same lift Wenger had given it 21 years ago.
However, one sour aspect of this episode is the way some Arsenal fans have reacted to this - as well as showing that they have short memories at the same time.
Those of you on social media will have noticed a Youtube channel by the name of Arsenal Fan TV - an outlet designed to let fans have their say.
Given the increasing disconnect between fans and the clubs they support, a channel such as this can let fans have their say with the chance that someone at the club is more than likely having a peek.
There are some who make solid, coherent points but there are others who take the attention away from them (presumably in a narcissist bid to get themselves noticed) by launching a series of tirades full of vitriol and bile against Arsene Wenger.
The below clip is one example. It features a chap who calls himself 'Troopz' (sic) and a word of warning for viewers of a sensitive disposition.... the English language is butchered like never before:
Former England international and current TV pundit, Gary Neville, criticised the grammatically-challenged Troopz and his ilk (there are others like him on Youtube if you care to look) for the venom that they were directing at Wenger.
Arsenal Fan TV asked Neville to do a question and answer session with them and their regular panellists (which he did) with Mr Blud Fam Troopz being in attendance.
Troopz said to Neville that people have mocked the way he speaks on the Fan TV channel and added (without a hint of irony) that if you "took away the blud and fam words I make some good points".
As hinted above, the irony seemed wasted on him because whatever good points he is making, they are buried amongst the blud and fam words he uses with increasing regularity - not to mention the swearing as well.
In short, he is giving the Wenger-must-stay brigade a free pass to dismiss his points.
I might be unfair to Mr Troopz and his ilk as he and most of them look to be of the age of starting to support Arsenal as boys just when Wenger first arrived.
Success and attractive football is what they were reared with and are now in a state of shock to see Wenger's formula start to malfunction due to old age.
Being closer to middle-age than Troopz and Co. I can remember Arsenal before Wenger and it wasn't pretty let me tell you - even when George Graham led them to two league titles. His style of play was hard-going on the eyes.
It was much worse during the back end of Terry Neill's reign. After they had sold the gifted Liam Brady to Juventus, it became evident how integral the Irish playmaker was to the team's success.
Cup runs home and abroad dried up as the team looked average without Brady and Neill's spell was ended when they lost at home in the League Cup to Third Division Walsall.
The Howe era was a mediocre one to say the least and will forever be remembered for a humiliating FA Cup defeat at Third Division York City in 1985.
One could imagine Troopz's head exploding - not before setting the world record for saying blud and fam the most times in a minute.
To hear today's fans wail and holler like screaming banshees when a microphone is shoved in their faces would have you thinking that Arsenal have gone back to the days of being humiliated in cup competitions by teams two divisions below them.
All that has happened is that the club have come full circle to the one season Bruce Rioch was in charge -neither going up nor down but stuck some way off those genuinely challenging for the league title.
Wenger gave them a team that attacked at will, scored goals aplenty, bossed teams about, won titles and cups and went on lengthy European runs.
In short, he spoiled them with success and gave them their greatest era.
The aforementioned era looks to be at an end and it is likely Wenger may well walk away once his contract expires at the end of the season.
Frustrating though the drop from sublime to 'merely good' must be to such fans, he doesn't deserve the vile invective that has come his way during the last 12 months.
Yes his methods do look to have gone flat but that's no excuse to discard his philosophy on a whim when it worked so well for the club these fans claim to support.
Some gratitude for your soon-to-be departing manager wouldn't go amiss lest it become apparent which club Spoilt B*stard, the character in the comic Viz, supports.