When the Royal Academy of Turku, now the University of Helsinki, was founded in 1640, the senior part of the school formed the core of the new university, while the junior year courses formed a trivial school.

To reflect this, the name of the Cathedral School was changed in 1840 to Högre Elementarläroverk, (lit.

In the education reform of 1872, the Högre Elementarläroverk and the gymnasium were merged into Svenska klassiska lyceum i Åbo, a Swedish-speaking classical school.

Since the Swedish Reformation in the early 16th century, the Cathedral School and its successors had been financed by the state.

In theory, the Katedralskolan is the oldest institution of learning in Finland as it has an organizational continuity from the medieval Cathedral school, founded in 1276.