Celtic have won their eighth Scottish Premiership title in a row - but how did they do it and could Rangers push them harder next season?
Neil Lennon's side cruised to a 3-0 win over Aberdeen at Pittodrie on Saturday to seal their 50th Scottish league crown and stay on track for an unprecedented treble-treble.
Celtic have won the treble in each of the last two seasons and now must beat Hearts in the Scottish Cup final on May 25 at Hampden Park to achieve the incredible feat.
Neil Lennon took over Celtic in late February after Brendan Rodgers' shock departure for Leicester, with the Hoops eight points clear at the top of the Premiership, and Lennon's men have been unbeaten since. Here, Sky Sports News reporter Charles Paterson looks at how they did it and what might happen next...
'Consistent, if unspectacular'
Endurance is the key word here. Lennon used it himself after the recent Old Firm win over Rangers, when a late James Forrest goal grabbed the points.
Celtic have outlasted everyone this season, at times going deep into stoppage time to secure results - notably at Dundee and Kilmarnock during the run-in. That is testament to the players' mentality as well as their fitness levels, which have been sorely tested at times.
Injuries have dogged the squad, with numerous important players sidelined at various points. Only Callum McGregor (56) and James Forrest (55) have largely remained unscathed, clocking up more than 50 games each in all competitions.
Kieran Tierney, Leigh Griffiths, Olivier Ntcham, Ryan Christie, Kris Ajer, Tom Rogic, Scott Brown and Mikael Lustig have all spent chunks of time out - Celtic have used 34 players so far in the league. The strength of the squad is vast, but it's been stretched to its limit.
Harmony within the squad was also tested early on after Dedryck Boyata's early-season mutiny, which was followed by the acrimonious departure of Moussa Dembele that left the striking department short-staffed.
The summer transfer window was decried by many as a failure, yet Celtic have actually stretched the gap to their nearest challengers and have picked up more points than they did last season.
Celtic have rarely hit the heights on the pitch that they did during the 'Invincible' season, but there have been standout periods. A demolition of St Johnstone in Perth stood out in October, as they scored 23 goals in five domestic matches.
Since the winter break, they have been consistent, if unspectacular, dropping only six points in total. At home, Celtic have been unbeaten in the league, winning every game bar two. On the road before Christmas form was shaky, but it's improved over the second half of the season.
Key men on the pitch
Forrest has continued his evolution into a potent weapon for club and country. Through the autumn he was almost unstoppable, scoring four goals in the first half at St Johnstone in a standout performance, form he continued on the big stage for Scotland in November. The goals have dried up somewhat since then, but 17 in all competitions for Celtic is by far his best return in a season.
McGregor epitomises consistency and must be the first name on the team-sheet every week. He has started 30 league games, more than any other player, and has rarely put in a poor performance.
His versatility is a huge asset; whether it be holding midfielder, attacking No 10, left back or at various points within a diamond, his influence across the pitch has been telling. It's no surprise that he's been talked about as a Player of the Year candidate.
Following the departure of Dembele and the self-imposed absence of Griffiths, Odsonne Edouard has stepped up to the plate to lead the forward line virtually on his own. The hefty £9m fee Celtic paid for him last summer has at times been questioned, but Edouard looks like a shrewd long-term investment.
His ability is unquestionable; the goal against Rangers in the third derby of the season was sensational, as were strikes against Hearts in November and Motherwell in February. As he matures, his consistency - and price tag - is likely to soar.
Continuity key after Rodgers
This is Rodgers' team, no question. His mark remains over Celtic's possession game and flowing football when in full flight. Defensively, early in the season Celtic were suspect, but since the winter break they have conceded just three league goals - a tribute to the work put in on the training pitches of Dubai.
Scott Bain's elevation to first-choice goalkeeper was a call made by Rodgers, and Bain has so far proved that to be a shrewd move. Lennon has already hinted he'd like to make alterations to the style of play, but he has changed little since arriving, allowing continuity to prosper.
It was fortunate for Celtic's chief executive Peter Lawwell that Lennon was available when Rodgers left. Leicester's move blind-sided the Celtic board, who had perhaps expected Rodgers to go in the summer, but not quite so soon.
Lennon has leaned heavily on assistant John Kennedy since taking over, and has hardly altered anything - a massive icon amongst the fanbase, he has also galvanised a support that was stunned and furious by Rodgers' departure. The transition could not have been smoother, but there was an element of fortune in the new manager's availability.
Celtic still way ahead
Celtic's early-season troubles were largely of their own making: an awful summer transfer window, a surprise Champions League exit to AEK Athens, and defensive vulnerabilities exposed. In January these wrongs were righted in the transfer market and on the training pitch.
On the pitch, the squad have a mentality that endures (that word again) which the competition can't match. Financially, Celtic remain way ahead of everyone, including Rangers, and as long as that gap exists, it is difficult to see when the divide will be bridged, unless there is an internal implosion.
Hunger for treble-treble
Another treble would be a remarkable feat, especially given the unpredictable nature of cup football, and Celtic are now just one win away from achieving that - they take on Hearts in the Scottish Cup final on May 25.
Celtic will always be favourites for the league, but cups have historically been shared about - the extent of their recent domestic domination is unprecedented.
There is a hunger about this squad that demands silverware, and with Lennon looking to secure the manager's job long-term, he will push his squad onwards to the end of the season as they seek that remarkable treble treble.
Celtic's defence is ripe for an overhaul this summer. Boyata looks like leaving as a free agent, Lustig and Izaguirre are both out of contract, while Filip Benkovic will return to Leicester and Jeremy Toljan to Borussia Dortmund. Centre-half is the biggest priority; indeed four new defenders may be required ahead of the Champions League qualifiers.
Midfield looks strong, but in attack Edouard stands alone for now - Timothy Weah and Oliver Burke's loan deals are expiring, while Griffiths' long-term future is uncertain as he recovers from personal issues. There are also questions over the goalkeeping position.
Lennon will look for funding, but he knows how it works at Celtic, and it's unlikely the board will spend anything comparable with that which they paid for Edouard. The balance of funding a push for Champions League qualification against the cost of missing the group stages altogether is one that must be found year after year. The EPL loan market may prove fruitful once again.
Will Rangers be stronger next season?
Rangers are realistically the only team who can - theoretically at least - compete with Celtic over a 38-game season. That would require smart recruitment, excellent management and a drop in levels from Celtic.
Rangers' recent recruitment has been mixed, and Steven Gerrard has already requested backing from his board for another push this summer; how much they can help him remains to be seen, although their work has already started in earnest with Jake Hastie and Steven Davis signing up.
Jordan Jones and Glen Kamara have also joined already, but Rangers need international standard quality to make a mark against Celtic - and they cannot afford a signing such as Edouard.
Financial losses of £14m have raised genuine questions as to the long-term strategy at Ibrox, and doubts about the capacity of the Rangers board to fund the playing squad to a level matching their rivals.
At the heart of next season will be Celtic's attempt to win a ninth consecutive league championship, matching their legendary side of the '60s and '70s, and Rangers' nine-in-a-row squad of the '90s. That landmark is a massive incentive for both teams to strengthen this summer, and recommence battle - but it's Celtic who hold the financial advantage.
Rangers' consistency since losing at Celtic Park in March has given their fan base hope for next season. If Gerrard can find a formula that produces that level of play across an entire campaign, the possibility of a more sustained challenge from Ibrox as Celtic push for a ninth title will increase.