A more helpful answer would be
"Pope Leo I was an Italian aristocrat, and is the earliest pope of the Roman Catholic Church to have received the title "the Great". He is perhaps best known for having met Attila the Hun outside Rome in 452, persuading him to turn back from his invasion of Western Europe. He is also a Doctor of the Church."
They don't appear to have been related if that's what you mean.
Quite why anyone posts an answer saying "use google" baffles me. Surely this is a Q&A site and if everyone were to suggest "use google" for every answer, the place would soon become very boring indeed.