Complex sentence: In 17 BC, an obscure Roman usurper called Scribonius headed a rebellion in the Bosporus, claiming to be a relative of the legitimate ruler Dynamis.
Split into simpler sentences: In 17 BC, an obscure Roman usurper called Scribonius headed a rebellion that broke out in the Bosporan. Scribonius pretended to be a relative of the legitimate ruler Dynamis.