When did Dunstable Grammar School end?

Dunstable Grammar School doesn't have a single definitive "end" date. It went through a series of reorganisations and mergers. While the traditional grammar school structure ceased to exist at a specific point, its legacy continued in various forms. There's no single year universally accepted as its "end." To get a more precise answer, you'd need to specify what you consider the "end" to be (e.g., the closure of the grammar school itself, the merger into a comprehensive, etc.).