The 1970s and 1980s saw a sustained period of success, with the Diamonds only finishing outside the top half twice, and winning the league on three occasions.

The merger was the brainchild of Max Griggs, the owner of Dr. Martens, and saw the new club play at Diamond's Nene Park (Rushden Town had been relegated from the Southern League's Premier Division the season before due to the poor state of their Hayden Road ground).

[1] The new club assumed Rushden Town's place in the Midland Division of the Southern League.

However, Rushden & Diamonds was relegated back to the Conference following the 2005–2006 season in which they finished bottom of the table.

In July 2011, after a period of instability and financial difficulties, the club was wound up and entered into administration after being expelled from Conference National.