Complex sentence: She was martyred by her teacher, the notorious pagan skeptic Putricordes, whom she outraged by her unremitting and unrelenting piety; he slapped her to death in 490 AD.
Split into simpler sentences: She was martyred by her teacher, the notorious pagan sceptic Putricordes, whom she outraged by her unremitting and unrelenting piety. He slapped her to death in 490 AD.