British Army Children’s School (BAC School) and Gurkha Army Children’s School (GAC School) were established in Malaysia and Hong Kong in the 1950s. However, in Brunei BAC School and GAC School were established during 1962-1963. Both schools were then located in the Medicina Lines and were housed in the same long wooden house. Half of this house was BAC School and the other half GAC School. The two schools shared a common football pitch. Later in 1973, Gurkha Children’s School (formerly GAC School) moved to Tuker Lines while Seria Service Children’s School (formerly BAC School) moved to Mumong. In the late 1990s, Gurkha Children’s School became Gurkha Children’s English School (GCES) and finally in September 2003, GCES and Seria SCS amalgamated to form Hornbill School.
Initially, the school was situated at five different locations within Tuker Lines and Mumong. With completion of the new build, the school finally came together in the current location in May 2011. The new build was officially inaugurated on 26th May 2011 by Her Royal Highness the Crown Princess of Brunei Darussalam, Yang Teramat Mulia Paduka Seri Pengiran Anak Isteri Pengiran Anak Sarah binti Pengiran Salleh Ab Rahaman.