The Brisbane High School for Girls (later to be known as Somerville House) was established with 39 students in the basement of the Baptist City Tabernacle at 183 Wickham Terrace, by Eliza Fewings in October 1899.

In July 1903, the boarders were moved again, this time to "Garth House" on Wickham Terrace, which was closer to the Day School.

Early in 1906, after Miss Fewings returned from a trip abroad, the boarding students were relocated once more to "Cheltenham", which was situated in what is now Jephson Street, Toowong.

[12] Constance Elizabeth Harker had been an acting headteacher and she and Marjorie Jarrett purchased the school in 1909, and so began their partnership as co-principals.

The two women had met while teaching at the Presbyterian Ladies' College, Sydney, where Harker was senior English and classics mistress.

As time went on, space became limited at the new site, and so Athol Place, a few doors away on the Terrace was rented for extra boarders and two primary classes.

In 1918, due to these financial struggles, they transferred ownership to the newly formed Presbyterian and Methodist Schools Association, while retaining their Principalship.

In 1920 the school moved from Wickham Terrace to its present site on Mater Hill, in South Brisbane, opening with an enrolment of 225 pupils.

The academic achievements of Somerville House during her co-Principalship were amongst the best in the state, and she widened the interests of her pupils by encouraging visitors who were authorities on literature, music, art and international affairs.

She encouraged good citizenship and social service, and during World War I formed the first school branch of the Red Cross Society in Queensland.

The school subsequently had branches of the Australian Student Christian Movement and the League of Nations Union, two companies of Girl Guides, and a Cot Fund which supported the ill and disabled.

[5] Pupils from north of the Brisbane River were transferred to Raymont Lodge, at Auchenflower, while those from the south went to the former Queen Alexandra Home, Coorparoo; boarding students were sent to Moiomindah at Stanthorpe, which became the school's administrative centre.

Based at Stanthorpe, the Principal at the time, Elinor Frances Craig, managed the three dispersed centres and frequently commuted by rail to maintain a presence in Brisbane.

The School Badge appeared for the first time on the cover of the June Magazine in 1902, and was designed by architect, Robin Dods.