Samogitia or Žemaitija is one of the five ethnographic regions of Lithuania. Žemaitija is located in northwestern Lithuania. Its largest city is Šiauliai. Žemaitija has a long and distinct cultural history, reflected in the existence of the Samogitian dialect.

For more than two hundred years, old Samogitia played a central role in Lithuania's wars against the crusading order of the Teutonic Knights (Knights of the Cross and Knights of the Sword). Invasions started in Lithuania in 1229.

In the 15th century, Žemaitija was the last region in Europe to be converted to Christianity. During the 15–18th centuries, it was known as the Duchy or Eldership of Žemaitija, which included some territories of what is now considered Aukštaitija and Suvalkija as well. The Duchy of Žemaitija was an autonomous administrative unit in the Grand Duchy of Lithuania with some similarities to a voivodeship.

After the partitions of the Polish–Lithuanian Commonwealth, Žemaitija was incorporated into the Russian Empire along with the rest of Lithuania. Žemaitija was the main source of the Lithuanian cultural revival during the 19th century and was a focal point for the smuggling of books printed in the Lithuanian language, which was banned by the occupying Russians.

After World War I, Žemaitija became a part of the newly re-established Lithuanian State.

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