key figure

n. an important person in an event; a person central to an event. Sam is not exactly a key figure, but he can lead us to Mr. Big.

Name	Pronounced	Usage
Shyla	-	English (Modern)
Penelope	pə-NEL-ə-pee (English)	Greek Mythology, English
Lysimachus	-	Ancient Greek (Latinized)
Charlton	KAHRL-tən, CHAHRL-tən	English
Philomela	-	Greek Mythology
Branka	-	Serbian, Croatian, Slovene