Founded in 1886, it was located about 2 km south of the town center of Allenstein (Olsztyn), at the Kortsee (Lake Kortowskie).

Kortau's first medical director, until 1891, was Eugen Hallervorden; he was succeeded by Adolf Stoltenhoff, who headed the hospital until 1917.

Among the 56 buildings in the compound was a bakery; there was also a church, used for both Protestant and Catholic liturgies, and a cemetery for deceased patients and staff.

Following the turn of the century, additions were made to the hospital, including bathrooms for therapeutic use, a lounge for patients with tuberculosis, and a surgical suite with modern X-ray equipment.

[2] In 1933, the hospital began compulsory sterilization of its patients, as was required by the Nazi Law for the Prevention of Hereditarily Diseased Offspring.

These patients had been identified as having traits, diseases, or conditions deemed in conflict with the Nazi policy of "racial hygiene".

They were among a group of 1,558 mentally ill inpatients from East Prussia and occupied Poland who were killed by a Schutzstaffel unit commanded by Herbert Lange, who was paid 10 Reichsmarks for each victim.

The transit centres' actual purpose was to thwart attempts by the patients' relatives and physicians to track their whereabouts.

[5][9] 500 patients were evacuated from Kortau in advance of the arrival of the Soviet 3rd Guards Cavalry Corps in Allenstein on the night of 21 January 1945.

The remaining patients and medical staff, as well as civilian refugees, were killed by the Red Army during its advance through the area.

In two months in the summer of 1950, almost 1,000 faculty and students from the Cieszyn campus alone moved to the abandoned hospital grounds.