ICONIC. Invincible. Irreplaceable. The verdict from the Celtic supporters on their captain Scott Brown. To them, he was all these things.

“I will be doing all I can to make sure I play my part in delivering more and more success to these fans," said Brown upon his arrival at Celtic in May of 2007. After over 600 appearances, ten league titles, six Scottish Cups, six League Cups and 14 years of sterling service, it would be fair to say he fulfilled that promise, and more than earned that tribute from the fans.

Celtic’s leader, who was appointed captain by Tony Mowbray back in 2010, has announced that he will finally leave the club this summer having agreed a pre-contract agreement with Aberdeen to take up a player/assistant manager role at Pittodrie.

It brings to an end a sometimes tumultuous, staggeringly consistent, regularly successful and rarely dull era where Brown was long the exemplar of the team on the pitch and the heartbeat of the squad off it.

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There may be arguments over his place in a team of Celtic greats when judged on footballing ability alone, but what is inarguable is that he departs as one of the most successful players in the club’s history, with a trophy to his name for every 28 games he played. He was also a much better footballer than many gave him credit for.

The mark of his impact on the club is measured in the outpouring of heartfelt messages which greeted the announcement by Celtic that he would be moving on. And while he may have timed his departure astutely due to his fading powers on the pitch, there must also be a pang of regret that his decision has coincided with a time when fans are unable to properly show their appreciation for the mammoth contribution he made over his time in Glasgow’s East End.

If anyone in the recent history of the club deserves the sort of emotional ovation at a packed Celtic Park not seen perhaps since the departure of Henrik Larsson, then Brown is that man. And it is a measure of his impact and service to the club that he would have surely been given that honour from the Celtic support.

If one moment summed up his Celtic career in the eyes of supporters, it is perhaps that famous day at Ibrox in early 2011 when ‘The Broony’ was born. Having curled a beauty into the top corner of Allan McGregor’s net to haul the 10-man visitors level, he turned to find the closest player was long-time nemesis El-Hadji Djouf. He immediately threw his arms aloft and stood in stony-faced defiance, and a moment of Celtic history was born.

Such incidents perhaps explain why he was so loved by Celtic fans and so loathed by many opposition supporters, with Brown revelling in his pantomime villain role. He became the living embodiment of the player fans love to have in their side, but hate when he is in the opposition ranks.

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To sum up almost 14 years in one short article is an impossible task, so perhaps I should leave the words of his various managers over the years at Celtic to do Brown justice. It was Gordon Strachan who brought him to Celtic for £4.4m from Hibernian, and it is fair to say he felt the club had got value for money.

“He wasn’t at his best when he first got to Celtic, for various reasons, which shows why we shouldn’t judge players too quickly,” Strachan once said.

“Now he’s up there with Billy McNeill in Celtic folklore, and that’s as good as you get. He’s one of Celtic’s most influential players of all time – he’s driven the team on for ten years.”

His next manager may take the credit for appointing him captain, but Brown revealed a few years ago that he was almost a casualty of Mowbray’s catastrophic reign at Celtic Park.

“It hit me like a hammer when he told me to find a new club,” Brown said. “I didn’t want to leave. I enjoyed playing for Celtic and all my family were here. But now I’m being told to find myself a new club.

“I had an offer from Newcastle. There had been also interest from Harry Redknapp at Spurs and I was waiting to find out if he was still wanting to do something. So I’m sitting there thinking if I should go or not.”

Thankfully for Celtic, Mowbray was the one who eventually left the scene, leading to one of the key relationships of Brown’s time at the club under Neil Lennon.

"Big players make the difference in big games and he's continually a big player for us," said Lennon of Brown. "He's inspirational. He just keeps churning out magnificent performances.

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"He is an icon at the club, a modern-day great.”

Brown had something of a topsy-turvy relationship with Ronny Deila, but the Norwegian was still moved to comment ahead of his own departure: "He has been unbelievably important. On the pitch and in training, he is unbelievable, he is always at 100 per cent.

“When I talked to the players the first day, I said we need players that give 100 per cent and he has been a good ambassador for that. He can handle a lot of pain as well and he is also a leader in good times and bad times."

Still, the omens didn’t look good for Brown when Brendan Rodgers swept into town, with the former Liverpool manager revealing he had been urged to ditch him. A heart-to-heart about his lifestyle followed, and Brown responded in style.

“He was absolutely magnificent for me,” Rodgers said.

“He’s a much better player than people give him credit for. There’s absolutely no doubt, if he wanted to he could have played at the top end of the Premier League – one, because of his personality and two, because of his ability.

“I couldn’t speak highly enough of him, what an incredible player he was for me.”

The final word though, as he looks to the future working with Stephen Glass at Pittodrie, should go to the man himself.

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“I still feel I have got a lot to give, not only on the pitch, but in a broader capacity as I embark on my coaching journey,” Brown said. "I will be relentless in my quest for success for Aberdeen.”

Given the promise he made to Celtic fans upon his arrival almost 14 years ago, these are words which should excite the Aberdeen support.