Jelgava is a city in central Latvia about southwest of Riga with about 63,000 inhabitants. It is the largest town in the region of Zemgale. Jelgava was the capital of the united Duchy of Courland and Semigallia and the administrative center of the Courland Governorate . Jelgava is situated on a fertile plain rising only above mean sea level on the right bank of the river Lielupe. At high water the plain and sometimes the town as well can be flooded. It is a railway center and is also host to Jelgava Air Base. Its importance as a railway centre can be seen by the fact that it lies at the junction of over 6 railway lines connecting Riga to Lithuania, eastern and western Latvia, and Lithuania to the Baltic sea.