The 1967 European Cup winner's medal won by Celtic match winner Stevie Chalmers could fetch up to £250,000 at auction in Glasgow next month.
The medal was presented to the late Celtic legend after the club defeated Italian giants Inter Milan 2-1 in the final at the Stadium of Light in Lisbon, Portugal.
Chalmers' winning goal in the 84th minute secured Celtic's place as the first British club to win the trophy, and legendary status for the players, who were immortalised as the "Lisbon Lions".
McTear's, who will sell the medal on behalf of Chalmers' family on March 13, described the gong as "one of the most important pieces of British football memorabilia ever to come to auction".
It will be included in a single lot comprising the six medals presented to the Celtic great in the historic 1966/1967 season, and valued at £150,000-250,000.
Chalmers' family archive
Chalmers, who died last year aged 83, was an integral part of the side that famously won all five competitions they entered that season.
The other medals were for the Scottish First Division Championship, the League Cup, the Scottish Cup and the Glasgow Cup as well as the 1966/67 Commemorative medal.
Described as the "most important group of Celtic medals ever to come to auction", it is only part of a remarkable archive offered by Chalmers' family, worth a total of more than £400,000.
Other iconic items linked to the European final include the Inter jersey worn by Italian defender Gianfranco Bedin, which Chalmers swapped after the final, valued at £20,000-30,000; and Chalmers' own signed match programme, estimated at £500 to £700.
The Brazil jersey given to Chalmers by Pele following a 1-1 draw with Scotland at Hampden Park in 1966 - in which Chalmers scored the Scots' goal - could make £50,000 to £100,000.
Chalmers' son Paul, speaking on behalf of the family, said: "I was too young to go to Lisbon but I remember the house being really crowded as we all gathered to watch the game.
"It was a tight match and when Dad scored the winner the house erupted.
"The team were all good friends and the Lions remained very close after they all retired. Bobby Lennox lived along the road in Saltcoats and for as long as Dad was able, he would stop by to take him to Celtic Park. He also visited Dad faithfully after he was diagnosed with dementia in 2013 and the two of them would talk about family and friends and share a few songs too.
"The Brazil game was a real highlight for my dad. He was surprised, but very proud, when Pele came over to swap jerseys at the end of the 1-1 draw at Hampden. Although he scored Scotland’s goal the jersey should have gone to Billy Bremner as he was nearest when the final whistle blew, but apparently Billy had been a bit rough with the tackling so Pele turned to Dad and gave it to him.
"My niece, Vicki, was Dad’s biggest fan and they spent a lot of time together in Troon. When she passed away in 2016 Dad was devastated and his condition started to deteriorate.
"From 2016 to his passing in 2019 was a very difficult time for the family and the experience put a lot of things into perspective. Dad’s medals and other memorabilia are with his six children and their families and with Mum’s blessing we all decided that the time was right to let another football fan become custodian of the archive.
"We will still have a million memories to share and that is what’s important."
Brian Clements, McTear's managing director, said: "This is an incredibly important archive that tells a fascinating story of one of Scotland’s most famous footballers.
"Stevie Chalmers was a huge figure in the game and gained immortality with Celtic fans when he scored the winning goal in the 1967 European Cup final.
"It is extremely rare to find anything associated with the 1967 final appear at auction, but to see the match winner’s medal is quite remarkable.
"This is one of, if not the, most important pieces of Celtic memorabilia ever to come to auction and we expect there will be considerable interest from football fans and sports historians across the globe."
Chalmers played for Celtic for 12 seasons, during which time he won six league titles, three Scottish Cups, four League Cups and the 1967 European Cup.
He scored 236 goals for Celtic, making him the club's fifth highest ever goalscorer.
He also played five times and scored three goals for Scotland. He died on 29 April 2019, aged 83, following a battle with dementia.