Pothinus

Pothinus (early 1st century BC to 48 or 47 BC), a eunuch, was regent for Pharaoh Ptolemy XIII of the Ptolemaic dynasty of Ancient Egypt. He is most remembered for turning Ptolemy against his sister and co-ruler Cleopatra VII, thus starting a civil war, and for having Pompey decapitated and presenting the severed head to Julius Caesar.