"Frederick Casimir Kettler (German: Friedrich Casimir Kettler; 6 July 1650 – 22 January 1698) was Duke of Courland and Semigallia from 1682 to 1698. Frederick Casimir was the son of Jacob Kettler and Louise Charlotte of Brandenburg.In his reign the Duchy lost its geopolitical position and became Sweden, Prussia and Russia´s territorial subject of interests." - (en.wikipedia.org 13.10.2020)
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