Originally set up in Mountjoy near Lough Neagh in 1614, it moved to its present location in 1636.

The original intention had been to have a "Royal School" in each of Ireland's counties (James I Order in Council read, "that there shall be one Free School at least appointed in every County, for the education of youth in learning and religion.")

It is sometimes interpreted as 'never say die' however their strapline, 'Excellence Through Perseverance', reflects the original translation more closely.

[citation needed] A house system exists to facilitate healthy sporting and academic competition.

The names of houses refer to notable past headmasters, alumni or local geography.