Complex sentence: Ceylon Defence Force (CDF) was established in 1910 by the "Ceylon Defence Force Ordinance of 1910", which reformed the Ceylon Volunteer Force (CVF) that existed previously as the military reserve in the British crown colony of Ceylon.
Split into simpler sentences: Ceylon Defence Force (CDF) was established in 1910 by the "Ceylon Defence Force Ordinance of 1910". Which reformed the Ceylon Volunteer Force (CVF) that existed that the time as the military reserve in the British crown colony of Ceylon.