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a historic Baltic tribal union. Around the 13th century, the Selonians occupied the territory along the left bank of the Daugava River, in the southern part of what is now the Latvian SSR. Their lands also included part of the contiguous region now constituting the northeastern part of the Lithuanian SSR. The Selonians’ political and military center was the fortification (from the sixth century A.D.) and settlement of Sēlpils on the Daugava. The Selonians fought against the German crusaders, and in 1208 they fell under the German yoke. Later the Selonians became part of the Latvian people.