It was founded in 1746 by the Habsburg ruler Maria Theresa of Austria and initially run by Franciscan friars.

The Novo Mesto Grammar School is the oldest educational institution in Slovenia that has been in operation continually since its foundation.

The list of the first 66 students finishes off by a comment by the first dean Father Geodefredus Pfeifer (he said: we start with a modest and tiny flock).

It was soon evident that only an upper secondary school can provide the needed broad knowledge and built-up skills that are essential for successful studies at university.

Renovation work on the school building, which lasted 2 years, began with the celebration of its 250th anniversary in 1996.