Complex sentence: Banks had been the botanist on board the HMS "Endeavour" for the first voyage of Captain James Cook, as well as the driving force behind the 1787 expedition of the HMS "Bounty" to Tahiti.
Split into simpler sentences: Banks had been the botanist on board the HMS "Endeavour" for the first voyage of Captain James Cook. He was also the driving force behind the 1787 expedition of the HMS "Bounty" to Tahiti.