Complex sentence: The Vicariate Apostolic of Cambodia was erected on August 30,1850, which since 1860 was responsible for the provinces Phsar Dek, Chau Doc and Soc Trang of lower Cambodia, now part of Vietnam.
Split into simpler sentences: The Vicariate Apostolic of Cambodia was erected on August 30,1850. Since 1860 it was responsible for the provinces Phsar Dek, Chau Doc and Soc Trang of lower Cambodia, now part of Vietnam.