Complex sentence: The College was founded in 1696 as a preparatory school, King William's School, the school received a collegiate charter in 1784, which makes it one of the oldest institutions of higher learning in the United States.
Split into simpler sentences: The College was founded in 1696 as King William's School, a preparatory school. It received a collegiate charter in 1784, making it one of the oldest institutions of higher learning in the United States.