Complex sentence: In mid-May 1945 4ACS and 5ACS traveled together to Morotai where they remained until June when they departed as part of the Australian-led Battle of North Borneo.
Split into simpler sentences: In mid-May 1945 4ACS and 5ACS traveled together to Morotai. They remained on this island until June when they departed as part of the Australian-led Battle of North Borneo.