The foundation of the School came about in 1769 when
King George III granted a
Charter of Incorporation on 15 July, the School
Governors holding their inaugural meeting on 6 November in
Dublin Castle. The school did not open until 6 March 1770 with school pupil roll of 140 children, including 50 girls. The buildings housing the school were erected in 1771 in the
Phoenix Park, overlooking the village of
Chapelizod in the Liffey valley (in full view of the
Wicklow mountains). The chapel was designed by
Thomas Cooley, while thirty years later
Francis Johnston designed the extensions to the buildings. It first took in 90 boys and 50 girls as pupils (in the charge of an Inspector and Inspectress, assisted by the Chaplain and an assistant mistress) in March 1770. The site originally occupied but by 1922 its boundary walls enclosed thirty three acres. By 1808 the system and organisation of the school followed closely that of its sister school, the
Duke of York's Royal Military School (then at
Chelsea, London,
England). By 1816, when Thomas Le Fanu (father of
Sheridan Le Fanu) took over as chaplain, there were 600 children at the school. In 1853 the school's first
"stand of colours" were presented by the then
Prince of Wales and, in the same year, the girls at the school left to join their own separate establishment, the Drummond School, which was founded for them at
Chapelizod. Even before this, in the eighteenth century, there had been more boys than girls at the school. The school was intended to act as a feeder to the British Army, where in the mid-19th century, children as young as 12 could enlist in the Army but generally enlistment began at 14. In the eighteenth century, boys were more likely to go into other occupations than into the army. A statement made by
Earl Roberts statements in 1909 reported that 80 per cent of RHMS pupils were going straight into the army on leaving the school. By this stage the school was regarded as an excellent source of competent soldiers and non-commissioned officers. Many of the school's pupils carried acts of gallantry in the wars that the British Army was involved in. One such individual was
Frederick Jeremiah Edwards who was awarded the
Victoria Cross for extraordinary bravery in the First World War. A war memorial was erected in the school grounds to commemorate this former RHMS pupils who died in World War 1. Although more detailed analysis of service records and press reports has discovered more war dead than is recorded on the memorial. ==Relocation and merger==