Complex sentence: Latgale pottery ("Latgales keramika") being the most well-known subset of Latvian pottery as the eastern region of Latgale is the most prolific producer of wares.
Split into simpler sentences: Latgale pottery ("Latgales keramika") is the most well-known subset of Latvian pottery. The eastern region of Latgale is the most prolific producer of wares.