Did you know? BC or Before Christ are the years preceding the birth of Jesus Christ. It is used by historians, teachers, archaeologists, and others on the Julian and the Gregorian Calendars. It was created by Dionysius Exiguus in 525 AD who was determined to find a correct method for finding the true date of Easter. Instead, he figured out a dating system that would replace the old table at the time, the Diocletian Era. Wanting to focus around the incarnation or nativity of Jesus Christ, it is speculated that he based his calculations by the Gospel of Luke or counting backwards 532 years from the first year of his new table to prevent people from believing in the imminent end of the world.
Resources: Wikipedia and GotQuestions.org