The armoury was designed in 1895 by Chief Dominion Architect Thomas Fuller, and was opened the next year and work on the structure was completed in 1899. While the exterior is based on a medieval castle, it was actually one of the most advanced structures of its day. It was pioneering in its use of a series of Fink trusses to create a large interior space with no columns or walls, and is today the oldest surviving example of a such a building. It was also one of the first buildings in Halifax to be lit by electricity.
It has played an important part in many Canadian wars, being an important transit point for soldiers before departing by ship for the Boer War and both World Wars. After the Halifax Explosion the armoury provided shelter for many who had lost their homes.