Rick Everitt, editor of fanzine Voice of the Valley, said that polic estimates put the number of visiting supporters at 300 as they marched on the ground of Sint-Truiden, another of five clubs owned by Duchatelet, ahead of the Belgian side’s Jupiler League game against Eupen in the Jupiler Pro League.
Meanwhile in Northampton, Karl Robinson’s side saw their winless run extended to eight games as they lost 2-1 to the Cobblers in front of a travelling contingent of 1,424 Addicks fans, many of whom protested against the owner, holding a banner saying "We Want Roland Out".
Duchatelet has not attended a match at the Valley since 2014 and had previously claimed those against his ownership were “hotheads” and disaffected ex-employees.
But a sizeable travelling contingent included protest band The 2 Percent, who performed at the Grote Markt. Charlton supporters were also joined by those from Sint-Truiden, many of whom are also dissatisfied with Duchatelet.
Everitt told Standard Sport: “The fact that hundreds of Charlton fans have been willing to travel to Belgium while the team was playing shows the extent of the determination to get Duchatelet out.
“It was a fantastic turnout and if he does not sell we will be back in even bigger numbers next time.”
Duchatelet has consistently insisted that he will not sell up, with Charlton chief executive Katrien Meire saying in October that the ownership had not had offers and would not consider putting the club up for sale.
In a statement to Standard Sport a Charlton spokesperson expressed the club's “disappointment” at the fan protest.
“At a time when so many clubs are facing serious financial problems, it is also important to make clear that Charlton Athletic is in a healthy financial position with a secure long-term future.
“In Karl Robinson, the club has a young, highly-rated manager who has a proven record of achievement in League One.
“The club has continued with its commitment to meet regularly with numerous supporters’ groups to openly discuss all aspects of Charlton Athletic. This season alone senior club representatives have attended more than 15 fan meetings.
“We would also like to thank the 1,400 fans who travelled to Northampton for the League One clash against Northampton Town. In recognition of the support, Addicks fans who made the journey to Sixfields by club coaches travelled for free and were offered a free breakfast by the club at The Valley before departure.
“The club’s priority on the pitch remains a return to the Championship as quickly as possible, with a commitment to long-term stability off it.”
Whilst some supporters were on the continent those who travelled to Sixfields were treated to further disappointment from the Charlton squad, who have lost their last four games and find themselves a mere six points off the drop zone down to League Two.
Michael Smith and John-Joe O’Toole scored for the hosts either side of a Jordan Botaka goal for Charlton to secure a win for Northampton, who leapfrogged the Addicks to 15th in the Championship.
Speaking in his post-match press conference Robinson insisted the protest had not had an effect on his struggling side.
“We live in a world with freedom of speech – everyone has the freedom to do what they need to do,” Robinson told reporters.
“We’re employed to win games of football and we’re not doing that at the moment. We’re employed to worry what’s going on inside the white lines.
“Anything else external to them, that’s everybody else’s prerogative. That’s their freedom of speech. We have to stay strong as a team and believe in their talent. Hopefully they will do so and get some results.”