Medaille de Haute Silesie
Upper Silesia Medal

    The Treaty of Versailles had ordered a plebiscite in Upper Silesia to determine whether the territory should be a part of Germany or Poland. Three uprisings occurred, the last of which required a special deployment of the allied army of occupation troops for peacekeeping and to ensure a trouble free referendum. 
    See Silesian Uprisings  (Wikipedia page) for more detail on this.
    The medal was created on the 22 September 1921, by the inter-allied Government Commission of Upper Silesia to commemorate service during this time, either in the allied military forces or with the government staff.

   Description: 30mm diameter in bronze, with an pivoting oak wreath suspension. Obverse; an oak spray overlain by a Polish shield with a scroll bearing HAUTE SILESIE over. Reverse; the inscription "COMMISSION INTERALLIEE DE GOUVERNEMENT ET DE PLEBISCITE. 1920 -1922". 30,000 medals were apparently issued.

  Ribbon: Blue with a wide central yellow stripe.
   

Notes.
    British Forces served during the plebiscite as part of the Army of the Rhine, and they would be entitled to this medal but I cannot recall seeing one with other British material ?
    Oppeln (Opole) appears to be the epicentre of operations during this period. The Commonwealth War Graves Commission records that during the concentration of British war graves in Germany during the period 1924-25, 11 burials in Oppeln from the period 1921 were transferred to Berlin South-Western Cemetery, with 33 post war graves remaining in Oppeln.
    We could find only  9 graves with 1921 dates of death in this (Berlin) cemetery at CWGC, - I assume some (probably all) died during the peacekeeping operations during the Plebiscite, whether death was from natural causes or otherwise is unknown.:
Ayles, H. Sig. 2311321 R. Signals 23/08/1921
Hanson, O. Dvr. 1020332 62 Bty. RFA 07/06/1921
Mills, F. J. Spr. 1849188 RE Railway Transport Est. 19/08/1921
Paterson, W.  Pte. 2746563 2nd Btn Black Watch 03/06/1921
Reck, Frederick. Sgt. 7868168 5th Btn Tank Corps. 21/08/1921
Sawyer, L.Pte. 4435387 1st DLI 20/08/1921
Waknell, J. T. Sgt. 4435228 1st DLI 15/07/1921 (won the French Croix de Guerre)
Walsh, F. Pte. 7111229 Royal Irish Fus. 28/07/1921
Watkins, Frank Joshua. Sig. 2306972 R. Signals 01/07/1921
Can anyone shed some light on the above casualties or can anyone provide the names of the 33 graves remaining in Opole Town Cemetery ? the burials do not appear to be in the care of the CWGC.