When did the Dutch cease to be a major power?
Short answerAround the Third Anglo-Dutch War they fell out of the top tier, though they remained an important maritime power.
NotesThe change is placed around the Third Anglo-Dutch War rather than treated as a sudden extinction of Dutch power. The Republic remained a capable maritime nation but slipped from the top two or three powers toward roughly fourth or fifth place. Britain, France, and Spain increasingly occupied the positions ahead of it in this concise comparison. The answer distinguishes relative decline from collapse, an important caveat when tracing shifts in naval power.