Why did Halifax become important during World War I and World War II?

During both World War I and World War II, Halifax served as Canada’s largest and most important naval base.1

Its strategic significance was primarily due to its location on one of the world's largest and deepest ice-free natural harbours. This geography made the city an ideal site for military operations and a critical hub for maritime activity on the Atlantic seaboard. Throughout its history, the growth and importance of Halifax were consistently tied to military and trade policies, and the city functioned as a heavily fortified base for the British army and navy until the Canadian government assumed control of its defenses in 1906.1