What is under this sign you shall conquer?

"Under this sign you shall conquer" is a Latin phrase associated with the Roman Emperor Constantine the Great. According to legend, before the Battle of the Milvian Bridge in 312 AD, Constantine saw a vision of a cross in the sky with the words "in hoc signo vinces", which means "in this sign you shall conquer". He then had his soldiers paint the sign of the cross on their shields and banners, and went on to win the battle. Constantine attributed his victory to the Christian God and converted to Christianity soon after. The phrase "under this sign you shall conquer" is often used to refer to the power of belief and faith in achieving success.