Complex sentence: Elections were held in July 2012 to a General National Congress (GNC), which took power a month later, charged with organising a constituent assembly for authoring Libya's new constitution.
Split into simpler sentences: Elections were held in July 2012 to a General National Congress (GNC), which took power a month later. The GNC on the other hand is primarily concerned with organising a constituent assembly, which will write Libya's new constitution.