AMERSHAM & Chiltern Rugby Club's Colts side were crowned champions of the Bucks, Berks & Oxon League to finish off an unprecedented season of success in every age group.
The Colts' triumph means that the Weedon Lane club can boast a county or league champion at every level, from U13 to seniors - which caps a perfect campaign, considering the first teamers also survived relegation from National League Three on the final day of the season.
Club spokesman Andy Gillanders said: "This incredible achievement must be a record, as it is inconceivable that this has ever been done before by any club in the history of the game."
The first XV beat Buckingham in their county final to set the tone. The U15s drew 10-10 with Marlow to earn a share of their county trophy and the U16s got there with a 32-14 win over High Wycombe.
In all, the club are county champions at U13, U14, U15, U16 and senior levels, as well as being league champions at U15 and U16 level.