Complex sentence: In 1878 in East Frisia (Germany), the first breeding company was founded.East Frisia and East Prussia (today Russia, Lithuania, and Poland) were the most important breeding regions of the breed.
Split into simpler sentences: In 1878 in East Frisia (Germany), the first breeding company was founded. After that, East Frisia and East Prussia (today Russia, Lithuania, and Poland) were the most important breeding regions of the breed.