The first building erected (in 1737 for General Major Karl Ludwig Truchsess von Waldburg) was the Ordenspalais, serving as the seat of the Order of Saint John (Johanniterorden) on the northern side of the square. The Order had taken over the completion of its construction after the premature death of its original developer.Laurenz Demps: Berlin-Wilhelmstraße, S. 30, 42, 49–50.
