Question

Constantine saw a vision of:

A rider on horsesback

A flaming cross

An angel

The sun

Answer 1

you think?

Answer 2

From http://en.wikipedia.org/wiki/Battle_of_the_Milvian_Bridge
It is commonly stated that on the evening of 27 October with the armies preparing for battle, Constantine had a vision which led him to fight under the protection of the Christian God. The details of that vision, however, differ between the sources reporting it.

Lactantius states that, in the night before the battle, Constantine was commanded in a dream to "delineate the heavenly sign on the shields of his soldiers" (On the Deaths of the Persecutors 44.5). He followed the commands of his dream and marked the shields with a sign "denoting Christ". Lactantius describes that sign as a "staurogram", or a Latin cross with its upper end rounded in a P-like fashion. There is no certain evidence that Constantine ever used that sign, opposed to the better known Chi-Rho sign described by Eusebius.[5]