[4] The main building of the school is notable for its renaissance architecture, the work of William Wallace, until his death in 1631.

It is located next to Greyfriars Kirk, built in 1620, in open grounds overlooked by Edinburgh Castle directly to the north.

When built, the building's front facade faced north with access from the Grassmarket by way of Heriot Bridge.

[8] The grounds contain a selection of other buildings of varying age; these include a wing by inter-war school specialists Reid & Forbes, and a swimming pool, now unused.

On his death in 1624, George Heriot left just over 23,625 pounds sterling – equivalent to about £3 million in 2017 – to found a "hospital" (a charitable school) on the model of Christ's Hospital in London, to care for the "puir, faitherless bairns" (Scots: poor, fatherless children) and children of "decayit" (fallen on hard times) burgesses and freemen of Edinburgh.

By the end of the 18th century, the Governors of the George Heriot's Trust had purchased the Barony of Broughton, thus acquiring extensive land for feuing (a form of leasehold) on the northern slope below James Craig's Georgian New Town.

This and other land purchases beyond the original city boundary generated considerable revenue through leases for the Trust long after Heriot's death.

Only a minority (52 out of 180 in 1844) were fatherless, which meant, these critics argued, that poorer families were leaving their children to Hospital care, even through holiday periods, and the influence of disaffected older boys.

'Auld Callants' (former pupils) were prepared to defend the Hospital as a source of hope and discipline to families in difficulties.

McLaren pushed for the number of boys in the Hospital to be reduced and for the Heriot outdoor schools to be expanded with the resources thus saved.

[18][19] At its height in the early 1880s this network of Heriot schools, which did not charge any fees, had a total roll of almost 5,000 pupils.

[21] George Heriot's Hospital was at the centre of the controversies surrounding Scottish educational endowments between the late 1860s and the mid 1880s.

In 1875 a Heriot Trust Defence Committee (HTDC) was formed in opposition to the recommendations of the (Colebrooke) Commission on Endowed Schools and Hospitals, set up in 1872.

[24] There were elements in this scheme of a response to contemporary European educational reforms, such as that exemplified by the German Realschulen.

This was not just a matter of the Trust providing financial support, but was part of a policy of encouraging technical education in Edinburgh.

Provision was especially to be made for pupils to continue their studies after completing the higher classes of the new Heriot's day school.

In the same year Lothian Regional Council attempted to bring the school in to the local authority system, but the Secretary of State for Scotland intervened.