Constantine I (Flavius Valerius Constantinus) was Roman emperor from 306-337 CE and is known to history as Constantine the Great for his conversion to Christianity in 312 CE and his subsequent Christianization of the Roman Empire. His conversion was motivated in part by a vision he experienced at the Battle of the Milvian Bridge in Rome in 312 CE.
This is a companion discussion topic for the original content at https://www.worldhistory.org/article/1737/constantines-conversion-to-christianity/.