By Jove!

"by Jove" (40)

Jove was an older Roman name for Jupiter. He was the Roman god of the sky and had power over men and gods. If he was angry at a person he would throw bolt of lightening at them. The expression emphasizes a phrase and is a nicer way of saying by God.

~ Quinion, Michael Quinion. "By Jove" Worls Wide Words. 2008. August 26, 2008<http://www.worldwidewords.org/qa/qa-byj1.htm>

~ http://www.myastrologybook.com/Zeus-Jupiter-Jove-Wotan-Thor.jpg