Exactly one year ago, Ryan Christie ensured his place in Celtic's history with the winning goal in the League Cup final, securing the first leg of an unprecedented treble treble.

Before his intervention, Brendan Rodgers' side had struggled against Aberdeen's man marking, and were well short of their best.

That strike would be a glimpse of the next 12 months, as Christie went from second or third choice to the driving force in Celtic's midfield and one of their most valuable assets.

Here BBC Scotland take a look at the rise of the Inverness-born midfielder, from outshining England star James Maddison and ousting Celtic's match-winner Tom Rogic, to leading the Scottish champions' European charge.

Homecoming hero

Christie starred as Celtic beat Ross County 4-1 back in the familiar territory of the Highlands on Sunday. He missed an early penalty but converted the follow-up to fire the visitors in front. He then coolly restored the lead just before the break after Ross Stewart's header had levelled.

Now with 15 goals for Celtic this season - plus one for Scotland - the 24-year-old is the star man for the Scottish champions. With another League Cup final against Rangers less than a week away, could Christie again be the Hampden hero?

"He's grown in stature and he now owns that shirt," says Sportscene pundit Steven Thompson. "He's become such an important player for Celtic - he's just getting better and better."

In danger of being forgotten

"One thing I will say about Ryan is he is a real talent and he is going to be a wonderful footballer," said the-then Inverness manager John Hughes as Celtic looked to bring Christie to Glasgow in 2015. Just 20 at the time, he had played 59 first team games for Caley Thistle.

When he joined Celtic that summer, four other young recruits also made the move to Ronny Deila's side. In the end, Scott Allan made just 17 appearances. Saidy Janko only a few more at 20. Nadir Ciftci netted four goals in 26 appearances before being moved on. Only defender Jozo Simunovic made any sort of impact.

Christie looked like joining the list of unremarkable signings, making just six appearances under Deila after being brought back from a loan spell at Inverness, then just seven under Rodgers before another loan followed, this time at Aberdeen.

"He's a good example of giving it your utmost when you're not in the team," says father Charlie Christie, himself a former Celtic player. "Lewis Morgan is an example of that now. I've seen the days when Ryan was hugely frustrated sitting in the stand at Parkhead.

"He played and scored in a 7-0 win on the final day of the season against Motherwell. Ronny Deila said afterwards he maybe should have played him more often that season. That just increased the frustration for Ryan."

Outshining England's £20m sensation

Ryan Christie and James Maddison's record at Aberdeen in season 2016-17

Aberdeen fans had spent the first part of the 2016/17 season being wowed by on-loan midfielder James Maddison. Just three months younger than Christie, it was clear the Coventry-born player was destined for big things, and three years later he is inspiring Rodgers' Leicester City, who paid a reported £20m for him.

When Maddison, now an England international, departed Pittodrie in January to return to parent club Norwich, Christie replaced him. It was viewed by many as a step down for Aberdeen, with the skilful Englishman seemingly irreplaceable.

Instead, Christie outshone him at Pittodrie. In just 15 appearances - two less than Maddison made - Christie scored seven goals to Maddison's two. He also showed his ability to turn it on in big games, scoring in big wins at Hampden and Ibrox - venues where Maddison had come up short.

However, a year later he seemed to regress. Despite playing the whole season with Aberdeen, he scored just once in his last 18 appearances, and on his return to Celtic very few thought he even had a future at the club.

'He's added an extra yard'

By October 2018, Christie had featured in just five Premiership games, starting one. But in the unlikely setting of a Murrayfield semi-final against Hearts, he scored his first goal of the season. He added two more over the next two games, and hit seven goals in 12 to become a mainstay of the team.

Over the last 12 months his goal ratio has improved, with nearly one every two games, and after making his Scotland debut looks set to lead the national side's charge for a first major tournament in 22 years come March.

"I'm biased obviously but I think there's more to come," says Christie senior. "He's added an extra yard of pace to his game - he's going past men now.

"He loves the international scene, he's learning greatly from that and in European games. As we know, Celtic and Rangers domestically dictate 90% of the game, especially at home, but in Europe it's different, and it brings you on leaps and bounds."

Christie 'more athletic' than Rogic

Both Rogic and Christie started the win at Ross County, but while Christie has made 33 appearances this season, his fellow midfielder has made only 10.

The Australian was often who Celtic looked to when they needed someone to conjure up some magic. But Christie is now Celtic's "main man" says Sportscene pundit Michael Stewart.

"It's an area of the park where Tom Rogic was the main guy a year or 18 months ago," said Stewart. "But Ryan Christie, he plays in that area, but he also plays off the right, off the left, a little bit deeper.

"He's got more to his game, he's more athletic than Rogic, and that's allowed him to get to those levels and he's now the main guy in that team."