I'm doing more research. I looked it up in my handy encyclopedia, and it corroborates your claim.
It comes from the Canaanites, who called him Shaher (the Latin translates to 'light bringer [morning star]). The Jewish Shaharit still commemorates him. His twin was Shalem, the evening star. He announced the daily death of the sun, and gave him the Word of Peace (Shalom.)
That verse from Isaiah I quoted? Total ripoff of Canaanite dirge for Morning Star:
'How hast thou fallen from heaven, Helel's son, Shaher! Thou didst say in thy heart, I will ascend to heaven, above the circumpolar stars I will raise my throne, and I will dwell on the Mount of Council in the back of the north; I will mount on the back of a cloud, I will be like unto Elyon."
Anyhoo, Kings of kingdoms were thought to aspire to be the spouse of the Goddess, elevating them to the position of Shaher, making them a Lucifer by proxy.
Point conceded. Also I found a very interesting link while digging around, thought I'd share: