Complex sentence: The Provinces of Libya were prescribed in 1934, during the last period of colonial Italian Libya, and continued through post-independence Libya until 1963 when the Governorates system was instituted.
Split into simpler sentences: The Provinces of Libya were prescribed during the last period of colonial Italian Libya and continued through to post-independence Libya. The country was divided into provinces from 1934 in the colonial era to 1963 when the Governorates system was instituted.