Complex sentence: The Union became the Federation of Malaya in 1948 which became the Federation of Malaysia in 1963, following the admission of Singapore, Sabah (North Borneo) and Sarawak to the new federation.
Split into simpler sentences: The Union became the Federation of Malaya in 1948. The Federation of Malaya became the Federation of Malaysia in 1963, following the admission of Singapore, Sabah (North Borneo) and Sarawak to the new federation.