Ownership has changed on a number of occasions from the company's formation in 1865, and the brand is now part of MAN Energy Solutions.
The company manufactured steam engines, boilers, agricultural machinery, and mill gearing.
In 1940, Ruston & Hornsby purchased a controlling interest in the company; this co-operation led to the formation of Ruston-Paxman Group.
In 1962, Paxman acquired the engine controls division of the Curtiss-Wright Corporation and merged the two businesses under the Regulateurs Europa name.
In 1988, GEC merged its Paxman, Ruston and Mirrlees Blackstone diesels businesses with the Alsthom division of Compagnie Générale d'Electricité (CGE) to form GEC-Alsthom.