Complex sentence: Laponia was a historical Swedish province or "landskap" in the north of Sweden-Finland until 1809, when Finland was ceded by Russia, and the province split into Swedish Lapland and Finnish Lapland.
Split into simpler sentences: Laponia was a historical Swedish province, or "landskap", in the north of Sweden-Finland. In 1809 the eastern part was ceded by Russia, which in effect created a Swedish Lapland and Finnish Lapland.