In a timeline that I am writing there is a Moorish empire in the 1780s. What type of leadership would be most realistic, assuming this is as close to OTL as possible. Should it be a Caliphate, Sultanate, or just a generic empire? I want it to be fairly religious but also very liberal, and becoming more secular. The empire stretches across the north African coasts, and down the Nile for a long way. It doesn't quite reach the West Sahara of Sinai.