Complex sentence: Quezon and Osmeña were escorted by troops from Manila to Corregidor, and later they left for Australia and then the U.S. There they set up a government in exile, which participated in the Pacific War Council as well as the Declaration by United Nations.
Split into simpler sentences: Quezon and Osmeña were escorted by troops from Manila to Corregidor, and later left for Australia prior to going to the U.S., where they set up a government in exile. This government participated in the Pacific War Council as well as the Declaration by United Nations.