Harper sought to establish a school along English Public School lines, while seeking to accommodate the different culture of the modern colonial society. Classes commenced in the billiard room of Woodbridge under the guidance of the school's first Headmaster, Mr Frank Bennett. As would be expected of a young school, many trials and tribulations arose - all were conquered and the Guildford Grammar School we know today was born.
In 1900 the School moved from the Harper family home to its present site. The School quickly grew and encountered success in rowing and football, key sports then, as they remain so today. Guildford Grammar School had established itself as one of the four leading schools of the day, and together with CBC, Scotch College and the High School (Hale), established the Secondary Public Schools' Sports Association of Western Australia (the PSA). The Association today is regarded as Western Australia's pre-eminent group of independent schools.