Duchy of Courland and Semigallia

The Duchy of Courland and Semigallia was a Baltic duchy created in 1561, when the Livonian Order was dissolved during the Livonian Wars and its last master, Gotthard Kettler, became the first duke. The duchy covered Courland and Semigallia in western and southern Latvia and was initially a vassal of the Grand Duchy of Lithuania before passing under the Polish crown and, from 1726, the Polish-Lithuanian Commonwealth. Mitau, now Jelgava, was its capital and the seat of the Landtag. Under Duke Jacob Kettler in the mid-seventeenth century the duchy pursued mercantilism, built a merchant fleet and established short-lived colonies on the Gambia River and in Tobago. The nobility dominated the Landtag, and the dukes' authority was limited. Courland was devastated by war and plague in the early eighteenth century and later fell under Russian influence. It was annexed by the Russian Empire in the Third Partition of Poland in 1795.