In 1688 he transferred his allegiance to William III, who rewarded him with the earldom of Marlborough and a succession of commands in Flanders and Ireland.

• 1688年，他转而为威廉三世效忠，被封为马博罗伯爵，并受命接任法兰德斯和爱尔兰的司令官作为酬报。