The building was completed in time for the school's first year, 1875, with Charles Henry Pearson as founding principal. Pearson served as principal until 1879, when Andrew Harper took over. While other private (church-run) girls' schools had existed before PLC, the school was Australia's first school for girls to offer a program and education equal to that of a boys' school modelled on the great English Public Schools. The school's current motto, "Lex Dei Vitae Lampas" ("The Law of God is the Lamp of Life"), was introduced during the Second World War, as the original German motto, "Ohne Hast Ohne Rast", was deemed inappropriate.