Formed in 1910 and registered just a year later, the Fire Brigade Employees' Union of New South Wales was the first known trade union of firefighters in the world. By 1922 it had changed names to the Fire Brigades Association of New South Wales, but officers remained excluded. In 1948, the officers' and firefighters' associations formally amalgamated and were registered under the title of the New South Wales Fire Brigade Employees' Union. Officers joined firefighters on strike for the first time, over pay. Just a year later, in 1949, a splinter group of senior officers formed an independent Senior Officers' Association. By 1975, the Senior Officers' Association and the FBEU formally amalgamated. From 1990, the NSW Fire Brigade Employees' Union identified as the NSW Branch of the United Firefighters Union of Australia.