The squad of ten 11-17 year olds was among 795 competitors in 72 categories from all over Europe.
Their Head Coach, Robert Cullinan said: “Against the highest calibre opposition ever seen at any International tournament we've attended to date, collectively our squad produced five bronze, two silver and one gold /European champion.
“There were 216 medals available to 795 competitors, roughly a 25 per cent chance of any medal.
“We had an 80 per cent win rate. As Tiger Woods said ‘The more I practise, the luckier I get.”
Chris O’Neill, a coach at Grove Jiu-Jitsu’s Club, added: “The clubs are like an extended family and we rely on each other to get the best out of each other.
"When everyone else went on holidays, a combined team of coaches and athletes gave up this summer to train for the event and happily, it was worth all our efforts.
"We’ve just started back regular classes after the summer break and are recruiting actively if anyone else reads this and is interested.”
The Junior European Jiu-Jitsu Championships took place in Birmingham over September 17 and September 18.
For more information about the club, check out the Merville Ju-Jitsu Club Facebook page.