Complex sentence: The nature and composition of these Ryūkyūan missions to Edo evolved over the course of time, but their essential character mirrored the Ryūkyūan embassies to the Qing court in Beijing.
Split into simpler sentences: The nature and composition of these Ryūkyūan missions to Edo evolved over the course of time. The essential character of these diplomatic expeditions mirrored the Ryūkyūan embassies to the Qing court in Beijing.