The gang targeted the Newcastle United striker's home as part of a wider conspiracy to commit burglary in which two other plush homes were also broken into.
Footy ace Isak wasn't in at the time of the raid but when he returned home at 10pm on April 4 last year he found his outside bins in his TV room.
Newcastle Crown Court heard that footage obtained from his "doggy cam" captured the raiders lurking in his upmarket home in the upmarket Darras Hall area of Northumberland.
The 25-year-old's sports car was also taken in the raid but later recovered.
Brothers Valentino Nikolov, 32, and Giacomo Nikolov, 28, their sister Jela Jovanovic, 43, and her son Charlie Jovanovic, 23, were later traced by police and arrested.
Valentino Nikolov denied conspiracy to commit burglary, which the other three had admitted, and stood trial.
Nikolov appeared at the court alongside his co-defendant and ex father-in-law Safet Ramic, 58, who was accused of handling a safe stolen from Isak's house.
A jury today returned a guilty verdict on Nikolov after less than half a day of deliberating.
Ramic was cleared of any wrongdoing.
As well as targeting Isak's home, Nikolov was convicted under the same charge of raiding a property in leafy Jesmond, Newcastle, where £1 million worth of property was stolen.
He is also also struck with the group at a separate house in Whitburn, South Tyneside, where designer goods valued at over £100,000 were taken.
After the verdict was returned, Judge Robert Spragg told Nikolov: "A prison sentence is inevitable in this case.
"However, I want to know more about you so I'm adjourning for the probation service to prepare a report about you."
Speaking via an interpreter, Nikolov asked the judge: "Can I know why they found me guilty of these things?"
He also asked if he could appeal the verdict to which the judge replied: "You can make an application to appeal but I'm not going to discuss that with you now."
Jurors were told during the trial that Nikolov arrived in the country via a ferry to Dover from Calais with his three relatives on March 27 before making their way north via a Ford motorhome and Citroen C3 which were captured on CCTV.
Prosecutor Daniel Cordey said: "It is the prosecution case that they all travelled to the North East together as part of that conspiracy or agreement to commit high value targeted burglaries of residential properties."
Jurors were told the raid of Isak's mansion was the last of the three break-ins.
Outlining the details, Mr Cordey said: "That property was left unoccupied between 1600 hours and 10pm on the 4th of April of 2024.
"The burglary was discovered when the Mr Isak returned just after 10pm. He found his bins had been moved and entry had been gained by smashing a glass door leading from the back of the property to the TV room.
"Inside an untidy search had taken place and cash to the value of between £5,000 and £10,000 had been stolen together with jewellery valued at about £68,000.
"A Dudley safe left by the previous occupant was also stolen from the property.
"The keys to Mr Isak's motor vehicle were also taken. It was an Audi, it was then stolen but later found abandoned after a report from a member of the public who called the police.
"Inside the property was CCTV. That CCTV showed three men in the living room.
"One of those males, the prosecution says, can be identified as Giacomo Nikolov. He's wearing distinctive tracksuit bottoms with a PSG football club logo on the right leg."
A head torch was later found, believed to have been worn by one of the four during the raid.
Jurors were told that the first of the burglaries took place in Jesmond, Newcastle, where homeowners had left to go on holiday on March 30, 2024.
The following day a maintenance manager discovered the home had been broken into via the first floor, the court heard.
Further searches revealed the disappearance of a CBE medal along with gold coins, watches, and designer clothes and handbags, jurors were told.
Nikolov then raided a house in a gated cul-de-sac in Whitburn, around 15 miles from Newcastle.
The homeowner returned to the address at 3pm on April 1 to find her patio doors open and over £100k of goods including designer clothing missing, the court heard.
Mr Cordey told jurors that the Ford motorhome was found almost two weeks later in Birmingham and inside officers discovered designer handbags and purses linked to the crimes.
On April 13, the Citroen C3 was tracked to Walsall in the West Midlands where the occupants changed the number plates.
The vehicle was pursued but stopped and inside were Nikolov, who was the driver, and the other three relatives, the court heard.
Nikolov will be sentenced on Wednesday, March 19.
Following the verdict, North East Regional Organised Crime Unit detective constable Mark Armstrong said: "This is a fantastic result, which has been the outcome of an incredibly complex and comprehensive police investigation by several police partners.
"Burglaries are an insidious crime and causes a great amount of emotional and financial trauma to victims."
NEROCU Detective Inspector Shaun Fordy said: "This is just the latest example of the work being done as part of Operation Sentinel – our region wide approach to tackling Serious and Organised Crime.
"I want to praise the efforts of all our partners, and the teams involved. We will continue to pursue those criminals who target our communities, and we will bring them before the Courts.
"We also want to encourage people to continue to remain vigilant by locking doors and windows and report any suspicious behaviour or criminal activity in their community."
Christopher Atkinson, head of CPS North East’s Complex Casework Unit, added: "The Crown Prosecution Service has worked closely with the North East Regional Organised Crime Unit throughout this complex investigation.
"It is testament to the quality of that investigation, especially the effective partnership work between multiple police forces, that we have been provided with such a significant amount of evidence.
"This has enabled us to build a particularly robust prosecution case, which has been instrumental in securing convictions against those responsible for these offences."