I'm guessing they started at the same time as super rugby which was in 1996. Basically they were viewed by most rugby critics and fans as a bit of a laughing stock and the only reason for them existing was that the ARU needed at least 3 teams to make a meaningful contribution to the new super 12 format. It didn't take time for the laughing stock tag to wear off because the Brumbies are the most successful of all the Aust super rugby sides -- 2 super titles and 4 other finals appearances is not a bad achievement for a province with little rugby history behind them compared to NSW and QLD. BTW - prior to the Brumbies brand name they were known only as ACT who usually only formed to play overseas touring sides to Aust.