Complex sentence: On April 16,1920, ethnic Germans from the Banat sent a request to the Paris Peace Conference asking for the re-establishment of the Republic as the Republic of Banatia, this new republic to include not only the Banat, but also the neighbouring region of Bačka.
Split into simpler sentences: On April 16,1920, ethnic Germans from the Banat sent a request to the Paris Peace Conference asking for the re-establishment of the Republic under the name of the "Republic of Banatia". According to the request, this new republic would include not only the Banat, but also the neighbouring region of Bačka.