The name alludes to its beginnings as a rugby club founded by alumni of schools established by the Congregation of Christian Brothers.

In 1907, after only the second year in the Brisbane Premier Rugby competition, Brothers won their first premiership defeating Valleys 18 – 8.

Rugby Union was re-introduced in Queensland in 1929 and Brothers returned to the QRU in 1930, but it wouldn't be until 1945 that it tasted success.

The year 1963 saw the club struggle to field a competitive team but things began to turn around in 1964 with Premierships in 1966 and 1968.

The 1970s marked the start of a 'third golden era' for the club as 'A' grade premierships continued in 1971, 1973, 1974, 1975, 1978 and then an unbroken and unprecedented record of five in a row from 1980 to 1984.

In 2024, Brothers became the first back-to-back premiers since the Canberra Vikings (2001-2003), taking the club's 30th title defeating Wests by two points once again, with a final score of 29-27.

The long tradition of clashes with University (nicknamed 'The Red Heavies' or 'The Students') first began in senior competition on 8 June 1912, with Brothers running out victors 24 – 0.

† Brothers played under the name Merthyr Football Club in the QRL (Metropolitan) rugby league competition from 1917 to 1918 .

† Brothers played under the name Merthyr Football Club in the QRL (Metropolitan) rugby league competition from 1917 to 1918.

§ Merthyr also played South Sydney for the "Rugby League Team Championship of Australia" at the Brisbane Cricket Ground.

Ascot-Clayfield originally played out of Hamilton Recreation Reserve (now known as Hercules Park), but moved to Crosby Park in 1983, on the invitation of the Brothers Club President Bob Conn. Ascot Clayfield originally sported green and blue hooped jerseys but changed to a harlequin design in the late 1980s.

In 2013, with the participation numbers climbing above 50 teams and 740 players, the junior club moved its Under 6-9 age groups to Windsor Park.