Complex sentence: Polydore Virgil (c.1470-1555), English historian, of Italian extraction, otherwise known as PV Castellensis, was a kinsman of Cardinal Hadrian Castellensis, a native of Castro in Etruria.
Split into simpler sentences: Polydore Virgil (c.1470-1555) was an English historian, of Italian extraction, otherwise known as PV Castellensis. He was a kinsman of Cardinal Hadrian Castellensis, a native of Castro in Etruria.