Complex sentence: At the beginning of 2014, Libya was governed by the General National Congress (GNC), an Islamist-dominated assembly which had failed to stand down at the end of its electoral mandate in January 2014, unilaterally extending its power.
Split into simpler sentences: At the beginning of 2014, Libya was governed by the General National Congress (GNC). The GNC failed to stand down at the end of its electoral mandate in January 2014, unilaterally extending its power.