Complex sentence: It became the main opposition Party in Northern Nigeria after the Region was granted Self Governance in the 1950's, in the First Republic it maintained a steady alliance with Zikist NCNC against the NPC dominated Federal Government.
Split into simpler sentences: It became the main opposition party in Northern Nigeria after the region was granted self-governance in the 1950s. In the First Republic it maintained a steady alliance with Zikist NCNC against the NPC-dominated Federal Government.