The Medieval artefact was discovered in a garage in an undisclosed location by a son who was clearing out his late-father's belongings, before being brought to Yorkshire to be valued and auctioned.
Despite its "pitted condition", only a few swords from the era have survived, with most displayed in ancestral homes or museums.
It is thought the weapon dates from the 15th of 16th Century and originated in the Scottish Highlands.
Its condition meant that it was likely it had been buried, submerged or exposed to the elements for many years, according to Hutchinson Scott auction house in Skipton, where it sold last month.
The sword belonged to mercenaries in Scotland with its origins being in the Scottish Highlands.
Sword maker and master-at-arms at Macdonald Armouries in Edinburgh, Paul Macdonald, said he had hoped to get himself a bargain bidding on the antique, but was not prepared for the figure to rise as high as it did.
“I was surprised when it went up to £6,000 and then £7,000.
“But really I am glad that it has gone for a price that reflects its true value.
“Clearly, its significance has been recognised and you can only hope that it has gone to a good home and that it will be looked after.”
Mr Macdonald had hoped to use the sword to make a replica.
He believed the sword was used by West Highlander members of the ‘gallowglass’, or the elite mercenary warriors from Scotland who were employed to defend Irish chieftains from the 13th to 16th century.
They were hired for their fighting prowess and seen as effective bodyguards who were unlikely to become involved in local disputes.
Mr MacDonald said: “These swords were incredibly light and incredibly fast.”
The sword is now in London and is due to be shipped to Canada in the near future, with the new owner paying a 20 per cent buyer’s premium on top of the £30k sale price.