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The study of Polar Motion (PM) is associated with the work of the International Latitude Service (ILS), the International Polar Motion Service (IPMS) and the Bureau International de l'Heure (BIH), and then the International Earth Rotation Service (IERS). After reviewing briefly the history of early PM research, the scientific objective of the ILS including its realizing, and the activities of all the cited services and giving information on the PM time series available from mid-19th century to the present, important details on the events and results are presented over the period until 1922. It is shown, in which way the Geodetic Institute Potsdam contributed to the foundation of the ILS and took part in its activities through the work of Helmert, Albrecht, Wanach and Mahnkopf. Based on international scientific cooperation, the results were the rectangular coordinates of the Polar Motion from 1890.0 to 1922.7 at 0.1 year intervals, in particular those derived from the latitude observations at independent stations from 1890.0 to 1899.8, and those derived from the latitude observations at the ILS stations from 1899.9 to 1922.7.