The College was founded in 1829 by then-Lieutenant Governor of Upper Canada, Major-General Sir John Colborne (later Lord Seaton).
A $40,000 expenditure for expansion of the original structures was approved by the province for twelve classrooms, a public hall, a room for the principal, and beds for 60 more borders.
The improvements were complete by April 1877, with the centre block expanded and its main facade altered to more of a Queen Anne style blended with a modified Elizabethan.
Two story brick piers enhanced the corners and framed tall narrow windows, with the main entrance protruding forward, flanked by banded columns, more typical of Jacobean style.
An octagonal cupola surmounted the main entrance volume, surrounded by narrow pinnacles topping the corner piers, which all concealed chimneys and ventilation openings.
Old Boys (graduates of the College) and other figures helped prevent this, but in reaching the compromise, it was decided that the school would be moved to a new location out of the city centre.
The principal, then George Dickson, and the architect G.F. Durand toured private schools in the United States, and in February 1888, plans for the new buildings were presented to the government.
Faculty offices were moved to the Prep building, the infirmary, and any other spare spaces, including the principal's residence, Grant House.