Celtic's double treble will "stand the test of time", says goalkeeper Craig Gordon.
A 2-0 win over Motherwell at Hampden on Saturday in the William Hill Scottish Cup final made it another domestic treble for the Hoops under Brendan Rodgers.
Under the Co Antrim man, Celtic have now won all six domestic titles on offer in his two years at the club to make for an historic double treble - and their latest Ladbrokes Premiership title was the seventh in a row - and although they are favourites for every trophy at the start of the season, Gordon says their achievements should not be underestimated.
"We're very happy and delighted with the achievement to back up last year's invincible treble with another treble," the 35-year-old said.
"You can't even imagine how difficult a thing that is to do.
"For this group of players to manage that and do it in some style, it is a fantastic achievement and one that will really stand the test of time."
The arrival of Rodgers has been the driving force behind Celtic's dominance in the past two campaigns, and with the former Liverpool boss set to stay at Parkhead after being linked with a move back to England this summer, the Scotland number one said the consistency he has brought to Glasgow has been the secret to their success.
He said: "The consistency levels we have shown in the cup and the league over the past two seasons has been tremendous and we have to try and keep that going to achieve more great things with this team."
He added: "We just try and win football matches, and by doing that we give ourselves the opportunity to make history.
"I think he's the only manager to have two trebles at Celtic, so his name is in the history books as well as all the players that have played under him and it's there for everyone to see in years.
"It has not sunk in just yet, the feat of what we have actually achieved, but it feels good at the moment."
Motherwell goalkeeper Trevor Carson believes his side showed Celtic too much respect.
It took the Hoops only 11 minutes to get the breakthrough with a powerful Callum McGregor drive from the edge of the box, and when Olivier Ntcham added a second 14 minutes later with a 25-yard shot it was already all but over for the Steelmen.
Rodgers' side remained in control for the most part to clinch an unprecedented second successive domestic treble as well as complete the cup double over Well, who they beat 2-0 in the Betfred Cup final in November.
A dejected Carson said: "To lose in any final is disappointing.
"We said before the game 'no regrets' and at half-time everyone knew we could have done a bit more and maybe showed Celtic too much respect.
"Obviously they are a great side but unless you get close to them and stick a foot in, you are not going to win anything.
"We regrouped at half-time but the damage was done, which was disappointing.
"If Celtic score early it is going to be hard for any team to pin them back but even when they went 1-0 up there could have been more of a reaction.
"For 10 or 15 minutes after the first goal we looked shell-shocked and that is not the reaction you need against Celtic.
"They are champions for a reason. They sense blood and they attack you and got the second goal and it is hard to pin them back at 1-0, never mind 2-0."
• Livingston clinched promotion to the Scottish Premiership after beating Partick Thistle 3-1 on aggregate in the play-off final.